The TARDIS landed in a familiar place – well, a few hundred yards away from a familiar place, anyway. The Doctor wasn’t so sure about the date. The temporal manifold was definitely acting up since its five hundred year service.

It was definitely San Francisco, anyway. There was no mistaking the micro-resonances from the San Andreas fault.

Lake Merced looked just the same from the footbridge where the TARDIS had set itself down. The Doctor looked around and smiled at memories, recent and not so recent of walking by the lake on a warm evening with Grace by his side. He hoped he wasn’t too far out in time. He really wanted to see her again. Twelve years on Gallifrey, doing his mandatory jury service, had been more tedious than he expected. After the first four weeks he was itching to escape beyond the Transduction Barrier and explore the universe again. By the time he was released from his duty he was positively pining.

And he missed Grace far more than he expected. That was why he set course for Earth as soon as he left the Kasterborus sector again.

It was a warm evening, at least. The lake was placid. There were birds singing in the trees. It was quiet.

Too quiet. This was a leafy suburb, but even so, there ought to be more people about. Walking by the lake was a popular activity. They had rarely been the only couple doing that. So was boating and fishing, and on the other side of the water was the Harding Park golf course which was never short of players spoiling a good walk – as his old friend Oscar Wilde called that particular sport.

John Muir Drive was quiet, eerily so. There was no traffic, and no parked cars, either. He walked past three of the substantial detached houses and noticed the steel shutters over the windows and doors, as well as the garages where the cars, presumably, had been stowed.

Grace’s house was the same. The Doctor stood and looked at it carefully for a long time then he slowly approached the shuttered front door.

There was a note pasted to it. He was slightly surprised to see that it was written in Low Gallifreyan. Of course, Grace had travelled in the TARDIS long enough and often enough to have soaked up a considerable amount of background artron energy. Languages were no trouble to her with that handy Babel fish side effect.

It obviously meant that nobody could read the note except him. Even so she was cryptic about it.

“Doctor, I’m at the place where we rode out the Big One of 1906. Look in the garage for a way to get there.”

It was signed with the scribble that passed for her signature and a single X – for love.

He turned to the garage – It wasn’t shuttered. There was just an ordinary garage door on it. The sonic screwdriver made short work of the lock. He pushed the door up and looked into the wide space where she usually kept her car.

It was empty except for a motor bike. The keys were in the ignition and when he checked there was a full tank of petrol – or gas as they called it around these parts.

“Well done, Grace,” The Doctor said as he wheeled the bike outside and locked the garage again. If everyone was on holiday there was no point leaving the house open to burglars.

Of course, that was a ridiculous theory. Everyone was certainly not on holiday. If they were, the whole city had gone on the same trip.

The Doctor didn’t pay a lot of attention to speed limits on the empty roads. The scenic route around the lake quickly gave way to a wide trunk road and he turned off that onto an eight lane raised freeway that cut right across the city. He didn’t see another vehicle or another soul in nearly six miles of the journey.

He stopped once on the section of Interstate 280 was known as the John Foran Freeway. It occurred to him that there might be one very nasty reason for the absence of people.

No, the sonic screwdriver confirmed that there was no unusual radiation in the atmosphere, and nothing in the way of airborne bacteria or other effects of a ‘dirty bomb’. He looked up at tiers of low-rent tract housing on an incline above the Freeway. It all looked disturbingly empty.

The last leg of the journey was along Potrero Avenue in the Mission District, a densely populated area characterised by low rent apartments and cheap shops. There were signs that some of those shops had been broken into. There was likely to be nothing in the way of foodstuffs left in the convenience store or medical supplies in the pharmacy next door on the junction with twenty-fourth street. The Chinese food store had been ransacked, too. On the other hand nobody had seen any point in looting the electrical store despite some very expensive TVs behind the mesh shutter over the window, and the pawn shop was similarly unmolested.

People had taken what was needed for survival. They had no use for televisions or gold watches.

The red brick, Italian Renaissance edifice of San Francisco General Hospital was on the right. Technically it was not the same building where he and Grace had tended to the sick and injured in the aftermath of the 1906 earthquake. The sturdy old wooden building had survived the quake virtually intact and had been a sanctuary for all comers for weeks after the initial disaster. Nine years later, though, the new building replaced it, a huge complex including acute and long term hospitalisation and out patients services as well as pastoral care and shelter for the homeless of the district.

Parts of that building had been replaced and new wings added over the years, but The Doctor headed for the main entrance. The gate was closed, but he climbed over and headed towards the emergency department. That was where Grace would be if there was any kind of crisis going on in the city.

Here, at last, he found people – far more than he expected. Every seat in the waiting area was occupied and virtually every piece of floor apart from a few lanes kept clear for the nursing staff to move about.

“I’m looking for Doctor Grace Holloway,” The Doctor said to the woman at the reception. She immediately checked the staff records and then shook her head.

“I’m sorry, sir. There’s no Doctor Grace Holloway here. Are you certain that she is a member of staff here?”

“She’s not a regular staff member here,” The Doctor replied. “She usually works at the Bayside Memorial Hospital. But I think she may have come here to help out….”

“No,” the receptionist said. “I can’t see any staff member by that name. But….”

“But what?”

“There… is a patient by that name. She is in the Poulson ward. Are you a relative?”

“Yes,” The Doctor answered. “I’m her husband.”

The receptionist glanced at him and then at the computer screen. She gave him a very odd look, but she directed him to the ward.

The corridors were crowded, mostly with people who just sat in lines against the walls, trying not to get in the way of the people who were working in the hospital. They were quiet, resigned to waiting for a long time.

He found the Poulson Ward. He was very puzzled by it, but he found Grace Holloway in a bed near the end of the long room. The curtains were closed around it. He parted them cautiously.

“What year is this?” he asked.

“2040,” Grace Holloway replied. “Doctor… I knew you would come.”

2040. That meant that she was seventy-nine.

She looked older than that, not just because her face was lined and her hair iron grey and thinning. She was obviously sick. Her skin was pale and clammy and her eyes rheumy. Her hands shook when she reached out to him. He grasped them in his and drew her gently into an embrace.

“I got the message you left at the house.”

“I knew you would come. I knew you wouldn’t leave us at a time like this.”

“Of course I would come. Grace, are you all right? Why are you a patient in the hospital instead of running it?”

“I retired from medicine ten years ago,” she told him. “My hands shake too much now. I… had a minor heart problem last week. They insisted on me coming into the hospital. I’m all right, though.”

The Doctor put his hand over her chest and felt the slight murmur that proved she had suffered a very minor heart failure but was beginning to recover. He closed his eyes and concentrated, visualising her heart in his mind. He could see that she was gravely ill. She wasn’t going to die right now, but it was only a matter of time.

“Doctor, we’re all going to die,” she said.

“No, you’re not,” he assured her. “You’re going to be fine.”

“No,” she insisted. “Doctor… the world is going to end. We are all going to die.”

“What?” He leaned back from her in shock. “Grace, what do you mean?”

“I mean….” Grace began wearily. “Doctor… you must know what I mean. You’ve been to the future as well as the past. You must know about this.”

“No,” The Doctor answered. “Grace, the end of the world isn’t this year. Why do you think it is? What….”

“There’s an asteroid… a really big one… It’s called 2011 AG5 and it is on a collision course with the Earth. The best guess is that it will impact somewhere in the Pacific ocean. If it does massive tsunamis will wipe out most of the landmasses of the world.”

“Well, those next to the Pacific, anyway,” The Doctor commented. “You Americans do have a bad habit of assuming you ARE the world.”

But it all made sense now – the empty streets, the crowded hospital.

“The city has been evacuated?” he asked.

“Most of it,” Grace told him. Her voice was cracked and thin, now, but it was still hers. “They moved out the pregnant women and anyone under eighteen first. Then everyone under forty – except for those who had chronic or terminal illnesses or any disability that meant they couldn’t work. Everyone still young and fit enough to be useful if by some miracle they survive the impact.”

“Caves dug out of the Black Hills of Dakota?” The Doctor asked. “Or giant submarines that can ride out the flood?”

She giggled despite the dread situation. She, too, remembered the films that had suggested those ways of saving humanity – or at least a portion of the American part of it, anyway.

“I’m not sure what the plan was. I’m seventy-nine. I was never on the list.”

It was a pragmatic decision, of course. If only a small part of the population could be saved then young women who could reproduce, fit healthy men capable of labouring to rebuild a society in the wake of an apocalypse were the ones they should save.

At least it was better than taking those who could afford to pay for salvation. He knew of at least one planet where that had been the way of it when the evacuation ships were ready to leave.

But it was still a terrible choice to make.

“The receptionist, the porters, all the doctors and nurses here, they’re all over forty. The ones left behind?”

“Most of the doctors are at least sixty-five. They made allowances for qualified people up to a certain age, and some artists and poets, musicians, but apart from that, yes. They opened up the hospital to as many people as they could – all the ones left behind. A lot of the homeless were among those left off the lists. They came here. They tried to make it as comfortable as possible. There is food and medical supplies. We can live until the end… if we want to. There are suicides daily. Some people just give up.”

“I can take you,” The Doctor said. “I can take you away from this, right now. I have the TARDIS – I can take you to a safe place.”

“No, Doctor,” Grace told him. “I can’t do that. If you could take everyone in this hospital… if you could pick up all the people in every hospital and police precinct and train station in the USA… and then come back and get everyone else… then I would go with you. But… but I’m not such a coward, Doctor. I am glad you are here for one of two reasons. Either… either to ask you to help save the planet, or if you can’t… if there is nothing else you can do… then to say goodbye.”

“Grace….” The Doctor grasped her hands again. They really did shake a lot, but whether that was age, or fear, or emotion, or even remembrance of the love they had shared in past times, he wasn’t sure.

“I was thinking of you earlier,” she said. “Before they brought the afternoon tea around – I’d been asleep, and when I woke up I thought of a time, years ago, in the twenty-tens. You came to see me when I wasn’t expecting you to come. You were really odd… very sweet and loving, and very attentive.”

“That’s an odd thing for me to do? I thought I was always sweet and loving and attentive when we were together?”

He smiled whimsically as he said that, and she smiled in response. He leaned forward to kiss her on the cheek then he changed his mind and kissed her on the lips instead.

“For old times sake?” she asked.

“For all times. Grace, I will do what I can to stop this disaster that is coming to this planet. Will you come with me, Grace? Will you do that for old time’s sake?”

“No,” she said. “I’m too tired. I need to rest. I need to stay here. But please, please do what you can, Doctor. For me, for this planet….”

“I’ll do what I can,” he promised. “And I will be back when I am done.”

“That’s all I need,” she told him. She shifted her pillow and lay down on it. He pulled the blankets around her and leaned to kiss her again. She closed her eyes and slipped into another sleep before he turned away from her bedside.

He made it back to the car park before he cried. He couldn’t help himself. The overwhelming awfulness of the situation broke through every reserve he had. He cried for a long time then he climbed back onto the motor bike and kick started it.

He rode fast along Potrero Avenue, but not so fast that he didn’t spot a movement behind the curtains in one of those low-rent apartments. He stopped the bike and walked back to where he had seen a flash of colour – a red jumper and a blue baseball cap worn by a little boy of about seven years old who waved to him in an urgent way.

The sonic screwdriver was as good as a master key on simple locks. He reached the apartment easily.

“Hello,” he said to the child. “I’m The Doctor. Who are you?”

“I’m Jason Branagan,” he answered. “My mommy and daddy won’t wake up.”

“They won’t?” A sad premonition came into his thoughts.

“We all took medicine last night,” Jason answered. “But I was sick afterwards. I ate some cereal, but the milk was funny and mommy still isn’t awake and I’m hungry again.”

The Doctor’s hearts both froze. He guessed what had happened. He ran to the master bedroom of the apartment. A man and a woman were lying on top of the bedclothes, still dressed in day clothes. They were holding hands. The man was clutching a bible in his other hand.

It was too late. The bodies were cold. He could guess what sort of ‘medicine’ they had taken by the residue around their lips. They would have slept through the breakdown of their digestive organs and the eventual heart failure.

“Is anyone else in the apartment block?” he asked Jason when he went back into the living room. “Anyone who could make dinner for you?”

“No,” the boy answered. “Everyone else went away. But we didn’t go. Daddy said that God would save us.”

The Doctor nodded. He wondered briefly what had happened to shake the man’s faith so much that he wanted to kill himself and his family. Had he realised that his God wasn’t going to save him after all?

“I can’t wake them up,” he said. “They’re….”

He didn’t have to say it. Jason knew. Perhaps in his child heart he had known all along. The Doctor held him until his tears subsided.

“Come on, kid,” he said at last. “I’ll give you a ride on my motorbike and something to eat when we get to my place.”

He was sure that Jason’s parents must have warned him about talking to strangers at some time, but the boy went with him anyway. He lifted him onto the bike in front of him and rode a little less recklessly now as he headed back towards Lake Merced and the TARDIS.

Yes, of course, it would have been easier to return to the hospital where people were ready and willing to look after a lost victim of this crisis, but he felt keenly the need to reach his TARDIS and do what he could to keep his promise to Grace.

He brought the boy into the TARDIS and sat him in the armchair in his cosy drawing room corner of the console room. He gave Jason sandwiches and milk and wrapped a blanket around him before going to the console and setting an intercept course while he checked the database for details of Asteroid 2011 AG5.

The information in the TARDIS database was gathered automatically from any planet it came into contact with. As a matter of course, a measurement of the planet and its life-supporting capabilities was always taken, but if there were any computers on the planet, the TARDIS would interface with them and update any records it found.

The TARDIS had uploaded information about the Asteroid 2011 AG5. The Doctor read what the Earth scientists had discovered about it in recent years and then opened the backed up copy of the original document that had been replaced a few minutes before.

In 2011 when the asteroid had been identified, it had been measured at a hundred and forty metres in diameter, with a mass of four times ten to the power of nine kilograms and an absolute magnitude of 21.8. That was far smaller than the asteroid that humans assumed had caused the planet-wide catastrophe that killed off the dinosaurs. If it did, indeed, impact in the Pacific it would cause tsunamis that would destroy settlements all around the edge of that ocean.

If it impacted on a landmass it would also cause devastation – for at least a hundred miles around its crater. If it hit a major population area millions could be instantly killed. If it hit one of the poles, then it would cause sea level rises that would change the face of the planet forever. Any impact on a landmass would throw up debris that would blot out the sun and cause climactic change.

All of those scenarios would mean – not so much the end of the world, but certainly widespread loss of life and the end of civilisation as humans in the twenty-first century knew and understood it. Those who survived, whether through luck or government projects to save the population, would have an uphill struggle to live in the aftermath.

But, according to the further information added to the data on Asteroid 2011 AG5 between 2012 and 2015 that was all academic. The asteroid was due to pass close to Earth in early 2040 but without causing any problems at all.

“Yes, that was how it should have been,” he said to himself. Then he opened the updated file again.

The asteroid identified as being on a collision course with Earth was 2011 AG5, but now it measured ten times the original size – one thousand four hundred metres. It’s mass, density, absolute magnitude were all increased by the same proportion.

A rock that size could punch a hole through the Earth, The Doctor realised without any hint of hyperbole. If it didn’t do that, it would split it in half – perhaps quarters.

The Human race was doomed, even those that the governments of the world had tried to protect.

He checked the figures again and wondered why Asteroid 2011 AG5 was so much of a danger than the scientists in 2011 and 2012 thought it was. How could they have mistaken its size so very badly? How did they miscalculate the probability of it hitting the Earth?

He knew that Earth scientists in the twenty-first century still had a lot to learn about the universe, but they understood their own solar system very well for people who had not yet personally visited their closest neighbouring planet. They could accurately measure objects in space. They could do the complicated mathematics that predicted the movements of those objects.

They didn’t get it wrong.

And they didn’t get it wrong, now - nor did the TARDIS, which had begun making its own calculations.

“It doesn’t make sense,” he told himself. “It just doesn’t make sense.”

He brought the TARDIS close to the asteroid. He opened the door and stood at the threshold, looking at the space borne rock. He remembered a half-known fact about the Sol asteroid belt.

In ancient times, long forgotten, his own people, the Time Lords, had destroyed the planet that once occupied this orbit in order to obliterate a terrible enemy to all sentient life.

This asteroid was his responsibility.

“Mister… I mean… Doctor….” He looked around to see Jason standing there. “Is that… is that it?”

“Yes, it is,” The Doctor answered him. “It’s the asteroid that has everyone on Earth so frightened.”

“It’s big.”

“Yes, it is. Are you frightened?”

“A little bit. But Daddy said that God would save us from it.”

“Yes….”

The Doctor bit his lip as he sought a better response. He was never sure how to answer people who said things like that. He knew he had no right to dismiss their faith in their God. In fact, it was expressly forbidden for a Time Lord to interfere with the religious beliefs of any people.

But he knew in his hearts that faith of the sort the boy’s parents had held, at least until last night, was empty without some kind of action.

He wasn’t an avenging angel sent from God. He would never make such a claim. But perhaps it was more than just coincidence that his erratic TARDIS had brought him here to intervene in this crisis. Perhaps he was there to make a miracle happen for those who believed in them as well as those who didn’t.

“What’s that noise?” Jason asked, breaking into his reverie. He hadn’t heard a noise until the boy mentioned it. Now he turned and ran to the console, then ran back and closed the door.

“That noise is a proximity alarm,” The Doctor answered. “It’s telling me that there is another machine with dimensionally relative capabilities near us.”

Jason didn’t understand him, and The Doctor didn’t explain further. He was reading the data that scrolled rapidly down the monitor in front of him. He blinked rapidly as he took in the information nearly as fast as a computer could process it.

When he was done, he knew, apart from anything else, that the Earth scientists hadn’t made any mistakes at all. Their calculations had been one hundred per cent correct both in 2011 and 2040.

It was the asteroid that was wrong.

“I’m going to do something clever now,” he told Jason. “It won’t look very clever to you, but it is.”

The clever bit was materialising the TARDIS inside the space ship that was inside the asteroid. The ship was a sophisticated one with any number of shields, particularly the ones that stopped the solid rock it had displaced from pushing back and crushing it to pieces. Putting the TARDIS inside that ship was going to be tricky.

But he WAS clever and he knew that he could do it. there was a certain amount of resistance. The inertial dampeners inside the TARDIS couldn’t disguise the fact that it was being bucked about like a snowflake in a blizzard, and the time rotor screeched in sympathy with the over-stretched engines, but he managed it.

He even managed to materialise in the engine room, exactly where he hoped to be. He stepped out onto the metallic floor, aware of how loud his footsteps were against the low hum of the ion-spur engines.

There was nobody in the engine room. It would all be controlled from the bridge, just as his TARDIS was. Nobody would come down here unless there was a problem.

In a very few minutes there WOULD be a problem. He began working at eye-watering speed to reverse what had been done here. It was a job for a skilled temporal mechanic, and he WAS a skilled temporal mechanic. He only hoped he could finish the job before he was disturbed.

He just made it. He was stepping back towards the TARDIS door when a figure materialised in the unnecessarily twinkling light of a transmat beam. He recognised the species at once.

“If you want to live, I suggest that you transmat into your escape pod, along with the rest of the crew. In a few seconds this will be a very uncomfortable place to be.”

The alien raised a sophisticated ray gun, but a high pitched whistle from the engines confirmed The Doctor’s words. It fired once, missing him by several feet, and then transmatted away again. The Doctor stepped into the TARDIS and closed the door.

He watched the console and saw that the ship’s crew had got into their escape pod, which itself transmatted out of the asteroid before activating an emergency wormhole programme that whipped it away into another galaxy. Then he did something else that was quite clever. Instead of the TARDIS being inside the ship, inside the asteroid, he materialised around the asteroid and the ship. The asteroid had been reduced to the size of an American football when he reversed the relative dimensions.

He kicked the asteroid. It disintegrated into grey dust. Its molecules had been stretched and retracted too much. It could no longer hold its shape.

A small metal object clattered to the floor. The Doctor picked it up and brushed the dust off it. It was about the same size as a diecast toy space ship, but rather heavier, and there was quite a lot of amazing detail inside the tiny windows on the bridge deck.

“Jason,” he said, passing the ship to the boy. “A souvenir for you. It hardly makes up for what happened to your mum and dad, but you keep it, anyway.”

“Thank you,” Jason said, clutching the ‘toy’ ship as if it was precious.

The Doctor set his co-ordinates for San Francisco General Hospital. Due to capricious nature of the TARDIS he arrived exactly twenty-four hours after he left to find it a little less crowded than before. Those people who were still there were in a state of excitement. The fact that the asteroid had completely disappeared from its deadly trajectory had been announced on TV. The President of the USA had made a statement telling people to go back to their homes and try to pick up their normal lives.

The Doctor left Jason in the care of the paediatric department until there was a social services department to look after him. He showed his space ship to all the other children and drank orange juice. Some time, he would have to deal with the death of his parents, but when he did there would be professional people to help him through it.

The Doctor went to the Poulson Ward in the long-term geriatric department. A nurse stopped him at the door and gently spoke to him.

“No!” he exclaimed in a grief-stricken tone before running to the bed with the curtains drawn around it.

She was still alive, but it was clear she had taken a turn for the worse. She was only partially conscious and a life support monitor measured how weak she was.

“Grace,” he murmured, grasping her hand. “Grace, I’m sorry I took so long to get back.”

“You did it,” she whispered.

“Yes, I did. The world is saved. But Grace….”

“It’s all right,” she told him. “Talk to me. Tell me what happened.”

“It was deliberate,” he said, feeling he was talking for the sake of talking. “A Stygian ship…. No, you’ve never heard of them. They’re a scavenger race, intergalactic scrap merchants. They break up planets and stockpile the minerals. They used stolen dimension technology to increase the size and density of the asteroid which changed its trajectory and set it on a collision course with Earth. They….”

He stopped talking. He felt her hand slacken its hold on his.

“Grace, no,” he said. “Not now.”

“Yes, now,” she answered him. “It’s my time. I’m so very tired. It’s all right. I’m ready. I’m… glad… you’re here…. I’m glad to see you… to… say goodbye.”

“I… don’t want to say goodbye,” he protested.

“You… don’t… have to,” she said. “You will… see me again… many times. But… I won’t… see you.”

And that was the last coherent thing she said. A few minutes later a nurse came to switch off the monitor. The Doctor sat numbly watching her, hardly hearing what she was saying to him.

“I’m glad a friend was with her at the end. You know, of course, she was famous in her time. She developed all kinds of advances in cardio-vascular surgery. She even saved the President’s life… not this one, President Mendez, twenty years ago, when he was shot.”

“Yes… I knew all of that,” The Doctor answered. “She… was… a wonderful woman.”

He stood up and walked away. There was no reason to stay. Again he made it as far as the car park before the tears overwhelmed him. There were fireworks going off somewhere. People were celebrating the fact that the world hadn’t ended after all. He was glad for them.

After a while he stopped crying and went back to his TARDIS where he left it outside the accident and emergency entrance. He programmed his destination carefully, taking into account the problem with the temporal manifold. This time he didn’t want to be late.

It was early evening on a warm San Francisco day. The lights were on in Grace’s drawing room. He stepped towards the partially open French window. Grace was sitting there reading. She was wearing a nightdress and robe and her hair was drying after a bath.

She looked beautiful, as always. He watched her for a little while like that, feeling a little voyeuristic, but happy to see her looking so well.

She looked up and saw him. Her smile widened as she ran to his arms.

“Grace,” he whispered. “Oh, Grace, I am so glad to see you.” He buried his face in her hair and held her tightly for a long time, just treasuring the feel of her in his arms, the scent of her newly shampooed hair. “I’m so glad to be here.”

“It’s good to see you, too, Doctor,” she answered when he released her from that first, urgent embrace. “But what’s the matter? Have you been crying? You look….”

“I’m… all right,” he told her. “I’m all right now I’m here.”

Yes, he thought as he kissed her again, trembling with emotion but knowing he would never tell her way. Yes, she was right. He could see her any time he wanted… any time in her life. He never had to say goodbye to her again.