Rose and Jackie walked slowly around the huge nave of the Cathedral Notre Dame de Paris. Neither were especially expert on early gothic religious architecture. If truth be told, they only knew two things about this particular cathedral – First, that it was the setting for The Hunchback of Notre Dame, and second that it was badly damaged by a fire in the year 2019.

Since they were visiting in the year 2017, before the fire, they had mostly talked about the Hunchback. Rose knew that the book was by Victor Hugo, the same French author who wrote Les Miserables, but admitted that she had not read either. Even in paperback they were terrifyingly thick wedges.

So, they fell back on the films. Saturday afternoons in the days when Jackie hadn’t been able to afford Sky had introduced them to a couple of dark, shadowy black and white films and one in nineteen-sixties technicolour. There was also the 1996 Disney animation which they both, in all honesty, recalled much more easily.

“Don’t tell THEM that,” Rose said, glancing across the aisle to their respective husbands. “Christopher will have read the book in the original French and The Doctor will probably tell us he helped Hugo with the action scenes or something.”

Jackie laughed, though softly, because although she had never been especially religious, she didn’t think it was appropriate to laugh out loud in a cathedral.

Then she looked up disapprovingly at another noise that didn’t quite seem appropriate. Between the ground level and the high gothic arched windows there were dark recessed arches that were part of a balcony, possibly with some sort of architectural word to describe it, though Jackie didn’t know the terms.

She did know that at least two people were fighting up there, using some very unchurchlike words as they did so.

She would have given them a good old London piece of her mind if that wouldn’t have been just as noisy. As she watched, though, the fight ended in the worst way as one of the combatants pitched over the balcony headfirst. He landed with a sickening crunch right in front of Jackie and Rose.

Rose looked down at the stricken man, then up again to see the other man who looked at them all from above before pulling his head back and running. She turned around and despite a crowd of murmuring and milling tourists between them she met The Doctor’s eyes across the nave. She signalled and he gave chase up the steps to the balcony while Christopher came to her aid.

“He’s still alive,” Jackie said hopefully. She looked at Christopher, but he shook his head as he placed his hand on the stricken man’s chest.

“Too much internal damage,” he concluded. “I don’t think even my father could save him.”

Jackie gripped the man’s hand desperately hoping Christopher was wrong. But she knew in her heart he wasn’t.

“I… came… to… the wrong...” the man gasped as blood bubbled from his lips.

“Don’t try to talk, sweetheart,” Jackie told him.

“No… I have to tell you… wrong Notre Dame…. Take… Take….”

He sighed and she felt his hand go limp, but not before he had pressed something into hers. Jackie choked back a sob because although she was a tough as nails Londoner she felt the sadness of futile death.

While various people were on their mobile phones asking for police and ambulance, The Doctor came back to the sorrowful scene reporting that the one who had pushed the dead man over the parapet had somehow got away.

“I don’t know how. It’s a dead end up there. But he got past me somehow.”

“Not your fault,” Jackie told him. Any other time such an admission from Jackie would have elicited a barbed response, but this really was not the time or the place.

Things moved quickly after that. The police and an ambulance turned up. Jackie and Rose both made statements about what they had seen and were complimented on their very good French before The Doctor and Christopher got them away to a quiet café near the Cathedral where they drank coffee and tried to get over the shock.

“If people don’t stop getting killed when we go anywhere in the TARDIS I’m staying home in future,” Jackie said once the coffee had revived her spirits. “That was horrible. The poor man.”

“He wasn’t from around here,” The Doctor said. He put something down on the café table. Rose examined the small rectangle of plastic carefully.

“A Time Agent…? Like Jack used to be?”

“You half-inched that from the body?” Jackie accused him.

“It wasn’t easy with so many gawkers trying to get a picture for Snapchat,” The Doctor admitted. “But I had to make sure. He wasn’t wearing a wristlet, but the ID was dangerous enough. The French police don’t need problems like that.”

“He said… he was in the wrong place, not the wrong time,” Jackie protested. She opened her hand to reveal the scrap of paper the agent had given to her.

Not paper, in fact. Christopher examined it carefully and revealed that it was vellum, the very old material used for writing important documents before paper was made outside of imperial China.

“Vellum was made from the skin of animals - goats, sheep,” Rose said. “We did the history of writing at school. Everyone went for the veggie option at dinner before realising there was no point when the sheep was already dead long before it was made into shepherd’s pie.

“Still.…” Jackie was glad she wasn’t still holding the page.

“It’s in code,” Christopher said as he examined the words written in very old ink. “Not a complicated one. I think I can work it out.”

The Doctor smiled a little too smugly.

“I taught Christopher to do codes when he was a time tot,” he said.

“Really? You called your kids time tots?”

“No,” The Doctor admitted. “Just a figure of speech. We were never that whimsical on Gallifrey.”

“Got it,” Christopher said. “Strangely, the translation is in Latin.”

“A message not meant for the common sort,” The Doctor said.

“Unless it was for a Roman,” Rose pointed out. “The common sort of Romans spoke Latin, didn’t they?”

“But they probably didn’t read,” The Doctor reasoned. “And vellum didn’t come along till later. This feels like twelfth or thirteenth century.”

“You ‘felt’ the vellum for its century?” Jackie was impressed though she tried not to be. “Ok… so what does it say in Latin?”

“At Notre Dame find the angel of angles,” Christopher answered.

“Come again?”

“It’s a clue, I think,” Christopher admitted. “Rather a cryptic one.”

“Angel of the angles?” Jackie queried.

“Do you mean like geometry or like Anglo-Saxons were called the Angles?” Rose asked.

“Geometry,” Christopher answered. “Angelus Ipforum could also translate as angel of the corners, but I think angles is more correct. Of course, in Latin it isn’t as alliterative”

“If there’s an angel for geometry, where was he in double maths?” Rose wondered. “Anyway…. What are we going to do? He gave that vellum to mum, and he told her he had the wrong place. Do we try to find the right place?”

“You mean… like a quest?” Christopher asked.

“Oh, not if we have to go to America,” Jackie protested. “Not while that Trump is President.”

“Why would we have to go to America?” The Doctor asked.

“He didn’t say ‘wrong place’ or even ‘wrong cathedral’. He said ‘wrong Notre Dame.’ And the only other one I can think of is in America, but they say ‘dame’ like pantomime dame.”

“No, it doesn’t have to be that one,” Rose answered her. “Notre Dame is French for Our Lady, which is what Catholics call The Virgin Mary. My mate Letitia went to Our Lady High School. There must be thousands of Our Lady’s in the world.”

“But not so many that are Cathedrals,” The Doctor pointed out. He leaned over and took an IPad from Rose’s coat pocket. She had been using it as a guide book to the sites they had been visiting in Paris. He deftly googled Notre Dame Cathedral and presented four possibilities in Reims, Amiens, Strasbourg and Chartres.

“There is also a basilica in Nice,” The Doctor added. “But that’s not technically a cathedral, and its nineteenth century neo-Gothic, later than the others, much later than the vellum.”

“So… assuming he got the right country, and we are talking about strictly cathedrals, and strictly Gothic, we have four possibilities?” Christopher surmised.

“We? Meaning we ARE going to try to find what the poor man was looking for?” Jackie asked.

“I think we are,” Rose said, recognising a look on The Doctor’s face.

“I think it is important to find out why a Time Agent is looking for gothic angels, corners or no corners, and why somebody killed him for trying,” he said. “So… yes, we’re on a quest.”

“Fine by me,” Jackie said. “As long as you remember that we left the kids with Chris and Carya just for a long weekend. And I’m giving you due warning. If we get led to anywhere mentioned in The Da Vinci Code, I’m going home.”

“I second that,” Rose added. “And if any clue turns out to be ‘apple’ there will be trouble, too.”

The Doctor grinned. Christopher looked again at the clue on the vellum and then took the IPad to do another search.

“If we ARE on a quest, I think I know which Cathedral we need to visit,” he said turning the image on the screen towards his father while shielding it from the women. The Doctor’s grin widened.

“Fantastic!”

Chartres, in the Centre-Val de Loire, was a little less than fifty miles south-west of Paris, forty minutes by train, an hour’s drive by car once the city traffic was negotiated.

It was far less by TARDIS. They had time for a leisurely lunch in a restaurant near the Eure River before heading to their second Gothic cathedral of what was still the same day for them.

Jackie and Rose were still no experts on this particular architectural style, but they did start to feel that they recognised ‘gothic’ when they saw it. The tall arched windows and doors, the plethora of carvings and statues inside and out, the dozens of ornate stained-glass windows that turned the interior of the building into a kaleidoscope of colour all felt very familiar.

“I don’t know why you’re surprised by that,” Christopher told them. “You’re Londoners. Westminster Abbey is much the same style.”

‘I’ve been in Westminster Abbey ONCE,” Rose said. “On a school trip, when I was twelve.”

“Same here,” Jackie confirmed. “About the same age when I was at school. You’d be surprised how many royal weddings us south London kids don’t get invited to.”

Christopher found that strange. He had been bewildered by London’s loud, busy sprawl when he first came to Earth, but had happily set out to know all of its architectural and artistic treasures. He couldn’t understand why somebody born and raised amongst so much culture could fail to take advantage of it.

Jackie found his bewilderment part of his charm.

“So… what about this angel?” she asked.

“It’s on the south side of the south tower of the west façade,” Christopher answered.

“Façade! Why can’t they just say wall?” Jackie asked as they followed the directions back outside into the warm afternoon.

Actually, she had to agree that ‘wall’ wasn’t a grand enough word for any part of this Cathedral.

And glinting in the sunshine on that south side of the south tower was the angel, a tall, slender, androgynous creature with beautifully sculpted folds to its robe and exquisite detail to the wings held aloft.

And what looked like the biggest compass in the world held in its hands.

“Technically, it’s not a compass like we used at school for measuring angles,” Rose noticed. “It’s a sundial. Look, there is a sun symbol and a thingummy that casts the shadow to tell the time.”

“Gnomen,” Christopher said, for ‘thingummy’.

“And you’re quite right,” The Doctor agreed. “It IS a sundial, but the movement of the sun was measured in degrees, too, so it still makes sense.”

“So… is there a clue on it?” Jackie asked.

“There’s a date,” Christopher suggested. “1528.”

‘I’ll take your word for that,” Jackie said. “That’s a really wonky five and if that’s a 2 its almost worn away altogether.”

“It says 1528 in the online guide,” Rose confirmed. “Apparently that was the date when the wings and the sundial were added to the plain ordinary statue. But…. Oh… hang on....”

She tilted her IPad away from the sunshine to read the small print more easily.

“If we’re looking for something important about the statue then this is the wrong one. This isn’t even from 1528. This is a twentieth century copy.”

“So, where’s the original?” Jackie asked.

“In the crypt,” Rose answered after reading carefully. She glared at The Doctor. “Typical. Ever since I’ve known him he’s dragged me to underground bunkers, tunnels, ducts, morgues. A nice sunny south facing tower like this with lovely grass and flowers and an ice cream van over there by the gate isn’t good enough for him. It’s got to be a bloody crypt.”

The Doctor put on his most innocent expression, as well he might, and they headed back indoors, joining a tour that took in the crypt beneath the nave.

“Well,” Jackie said as they stood in front of the original statue, a thoroughly decayed and sorry sight with details crumbled and decayed. “That looks well old. But I’m even less sure about 1528. The five is more like a three and that two really looks more like a seven.”

“No,” Rose argued. “French sevens used to have a line through them. They stopped doing it just AFTER our school French books were printed, but they definitely did it back then.”

“So, what is important about 1528, anyway?” Jackie asked. Rose opened another tab on her IPad and Googled.

“Nothing that jumps out,” she admitted. “Even in the famous deaths the only one I recognise is Albrecht Dürer. He did that painting with the weird skull you can only see if you look at it sideways on. It’s in the National Gallery. That was a different school trip.”

“And I rather suspect it’s a bit of a red herring in this case,” The Doctor admitted. He looked closely at the statue. He turned to make sure the tour guide was busy with her back turned and reached to feel the back of the crumbled figure.

“I think there’s something written on the back.”

“Made in France?” Rose suggested.

“Very probably,” The Doctor admitted. “Or it could be our clue. Jackie, do you feel faint from being in this crypt for too long?”

“No, not really,” she answered. Then she grasped the hint and managed a thoroughly impressive swoon. After Rose screamed for good measure everyone’s attention was on Jackie. The tour guide insisted she was the registered first-aider for the Cathedral and set to work putting Jackie into the recovery position.

The Doctor worked quickly and nobody took any notice of him until he returned to the huddle around Jackie and suggested old fashioned smelling salts.

“Who carries ‘old-fashioned smelling salts’ around,” Rose answered. It was a perfect cue for Jackie who groaned and raised a hand to her forehead like an actress in a Windmill Lane farce. “It’s all right, mum,” Rose added. “It’s just your old problem. Let’s get you up and out of here. A nice cup of tea will make you feel better.”

Jackie leaned on Christopher and kept up the pretence until they were out of the Cathedral and blinking in the sunshine.

“Tell me it was worth it?” she demanded of The Doctor, but he just gave her his toothiest grin.

It HAD been worth it, but The Doctor didn’t explain why until later. First, even though Jackie hadn’t really fainted, he knew that she and Rose were nearing cultural overload. He booked them all into a hotel in the middle of Chartres and they had a nice dinner and a good night’s sleep before setting off to their next destination.

“Ravenna?” Jackie queried. “I’m sure I’ve heard of that place, but I can’t think why.”

“It is where Dante Alighieri lived for much of his exile from Florence,” Christopher answered.

“No, I think I can definitely say that’s NOT what I was thinking of,” Jackie answered. “Probably some footballer comes from there or something.”

Rose and Jackie had googled a few useful websites before the TARDIS landed at their destination, just so that they wouldn’t look completely devoid of education. They therefore knew that the building they were looking at was two decagonal orders of Istria limestone – in other words two ten sided structures, one on top of the other like a wedding cake, made of stone from a place in modern day Croatia. They also knew that the Mausoleum of Theodoric was built in 520 AD by Theodoric the Great of the Ostrogoth kingdom, as his future tomb. They had come to terms with the idea that somebody would have their own tomb built before they were dead. After all, the Pharaohs of Egypt did that. And plenty of people arranged for a plot in their local cemetery well before their time.

They had even looked up the differences between Goths, Visigoths and Ostrogoths and knew none of them had anything to do with the kind of people who favoured pale make up and black clothes.

“But that doesn’t look anything like the gothic architecture we were just getting used to,” Rose pointed out as they approached the building through the green and pleasantly laid out Parco di Teodorico. “Those arches in the lower section are too stubby and rounded and there are no big windows.”

“Gothic architecture isn’t connected to the Goths,” The Doctor explained. “It was popular with the Norman French and branded ‘gothic’ implying dark and forbidding by critics who didn’t understand the architecture - or the Goths, for that matter.”

“Confusing,” Jackie sighed. “We ARE sure we’re in the right place, aren’t we?”

The Doctor coughed in a thoroughly embarrassed way as even Christopher allowed himself a wry smile. While Jackie had been distracting everyone within her spectacular faint, The Doctor had photographed the back of the Chartres Angel’s sundial with Rose’s camera phone.

Unfortunately, his thumb had obscured some of the letters.

“You try taking photos backwards, in a hurry,” he told them all. “Besides, Christopher sorted it out already.”

Again, the apparently random letters etched into the carving had been what The Doctor called an Atbash substitution cipher. Rose and Jackie had googled it so that he wouldn’t have the satisfaction of explaining what that was. Jackie had also added that they had puzzles like that in the Mandy and Jinty and other comics for girls she had read as a girl. The only clever bit was having the decoded message in Latin, and even that didn’t really matter with the TARDIS translation radiation in their heads.

“…the… something…. of Ostrogoth Théodric’s tower,” Jackie said. She looked at the two-storey mausoleum in grey-white stone, darkened in places with age. That sounded right, anyway. But WHAT exactly were they looking for?

“I’m pretty sure the partially obscured word is monolitus,” Christopher said. “Which means….”

“Monolith,” Rose said. “Doesn’t take MUCH working out to get that one.”

“But where is there a monolith in this place?” Christopher asked.

Rose and Jackie looked at each other. They loved their men. They were proud that both of them were pretty much geniuses.

But it was nice, just for once, to know something they didn’t.

“You should Google more often,” Jackie said. “All the websites, even the ones badly translated from German into Italian and then to English mention that the domed roof is a monolith, meaning that it was carved from one single piece of stone before it was sent all the way over from Istria.”

All four of them looked up at the roof dome. It wasn’t as impressive as St. Paul’s or El Duomo in Florence, but when you knew, as Rose and Jackie did, if only from the Wikipedia page, that it was ten metres in diameter and weighed two hundred and thirty tonnes, a certain amount of awe was called for. Even the Time Lords hadn’t carved, hauled and raised anything like it.

“Our next clue… or possibly whatever it is we’re looking for… is somewhere on the roof of the Mausoleum,” Jackie surmised. “Before we go looking for it, I’m giving you fair warning. I’m not providing any more distractions. That bloody crypt had a really cold floor.”

The Doctor agreed that she had done her duty distraction wise while Christopher went to the little wooden kiosk where he paid four euros each to view the UNESCO World Heritage site. Rose smiled as she recalled a rather cheapskate review on TripAdvisor that suggested viewing for free from outside the fence. They were going inside.

They got their money’s worth, following the official tour through one of the exterior arches which, apparently, had fine examples of joggled voussoirs. Rose and Jackie decided they didn’t care what a joggled voussoir was and had no intention of either asking the men or Googling it later. They were happy to live in that much ignorance.

Beginning in an undercroft and working back up into the ground floor before finally going up an exterior stairway and around a balcony retrofitted with safety railings it wasn’t an especially edifying tour for anyone not especially interested in Ostrogoth history. The interiors were basically just grey-white walls with some small, high slits letting in light.

“Even Christopher is bored,” Jackie whispered to Rose. “I know that look. He has it in parliamentary debates.”

Rose suppressed a laugh and, ignoring the porphyry Roman bathtub allegedly repurposed as Theodoric’s sarcophagus which had most of the tourists pulling out their camera phones, she looked up at the roof. The single piece of rock carved into a dome was somewhat awesome, and a little scary. She felt as if she could feel the weight of it on her head. She didn’t like to hear about the crack near the centre which might have been caused when the roof was raised to make the walls higher some time in the ninth century. She didn’t listen to the guide explaining to a German couple how ninth century masons could possibly achieve such a feat.

She was trying to see something on the roof that might be their clue, but it was impossible. There were all sorts of fine lines, possibly tool marks from when the dome was carved, more likely just random lines etched by time. If she squinted and used a lot of imagination, some of them might have looked a bit like letters, but she knew it was just imagination.

“The message is there,” The Doctor said. “It’s invisible.”

“Invisible?” Rose put a whole level of scepticism into that one word.

“Invisible,” The Doctor repeated. He adjusted the sonic screwdriver and checked that most of the official tour were still busy looking at the Roman bathtub and debating whether it really was the actual sarcophagus of Theodric or a later substitute after a Christian sect had disposed of his pagan bones. He shone an ultra violet light around the circumference of the monolithic roof.

He was right. Letters appeared like ghosts. Rose gave up trying to memorise them. By the way The Doctor’s lips were moving he was doing it anyway, and his Time Lord memory was bound to be up to the job.

“Yes… but… I don’t get it,” Rose pointed out as they headed into Ravenna for lunch. ‘We’ve been going on the idea that these messages were hidden centuries ago in old places. But invisible ink…..”

“Leonardo da Vinci invented a form of invisible ink,” The Doctor answered.

“Oh, he would, smart Alec,” Jackie remarked.

“I’ll tell him you said that next time I drop by,” The Doctor countered as Christopher diplomatically suppressed his laughter. “But in fact the message wasn’t written in ink. It was in blood.”

“Blood?” Rose and Jackie both cried out in alarm. “You mean…. Human blood? Somebody…. Killed somebody else…..”

“Not necessarily. It wouldn’t have taken a lot. The point is, even old blood, after it has faded, still shows up under black light. So I got the message.”

“But the message must have been put there before anyone knew about black light and UV and all that,” Rose argued. “I mean… I know Luminol… that they use in forensics…. They go on about it in TV cop shows… was around during World War Two. Because I saw a film where they used it way back then. And didn’t Isaac Newton invent UV light?”

“You’re right about the Luminol, but it was a German called Johann Wilhelm Ritter who discovered the ultraviolet wavelengths. But since that was in 1801, your point still stands. My guess is that the message is from around the same time as the others…. Sixteenth century at the latest.”

“So, did whoever put the message there have future information… like us… like a time traveller?” Even Jackie was coming to conclusions of her own.

“Maybe, or maybe he just hoped somebody would find a way of reading it,” The Doctor answered. “I am more than a little curious about that. We did start out with a dead Time Agent after all.”

“But the real point is why somebody did all of that,” Christopher said. “What is it we’re on a quest for and who laid these clues … as well as how… and when.”

“That’s a lot we still don’t know,” Jackie said with a weary sigh. “For all we’ve done already.”

“And I think we need the answers to some of those questions before we go any further,” The Doctor said. “I’m going to get some expert opinion on this.”