Marion was enjoying an extended stay in Rio. The trip to Brazil had originally been intended only as a day trip to enjoy the peaceful delights of Parque Lage, but Kristoph liked the place so much he decided – to Marion’s delight – that they should stay longer. They travelled up to Mount Corcovado and the statue of Cristo Redentor again, this time coming back down in the TARDIS and parking it, disguised as a fine wardrobe, in the honeymoon suite of a five star hotel booked retrospectively for their stay.

They explored the museums and art galleries and the best restaurants of the lovely old city, sat on the famous beach of Copa Cobana under the shade of big umbrellas, drank lots of big fruit drinks with much smaller umbrellas in them and enjoyed the same beach in the balmy cool of the fragrant evenings. They even sat on the veranda of a samba club near the high water mark and listened to the music and noise inside from a safe, refined distance. Neither quite felt like dancing a samba, but they loved to hear the insistent beat of the music.

And at the end of the week it was Carnaval. Kristoph was doubtful. He wanted Marion to have a restful holiday. That sounded far from restful. But they wouldn't have really experienced Rio de Janeiro without seeing the Carnaval.

“We shall have the best possible VIP seats, then," he decided. "No pushing and shoving in the streets."

Marion usually preferred to experience such things in the ordinary way, not from grandstands, but in this instance she readily agreed with her husband. Carnaval was so much bigger and louder than anything she had experienced before and she couldn't help being a little nervous.

She had seen parades before, of course. Liverpool was a city with a rich culture and plenty to celebrate. In her lifetime the Garden Festival had rejuvenated a run down part of the city and brought thousands of tourists. There were annual street festivals for Chinese New Year and celebrating the Caribbean community in Liverpool. She had even been around the swollen numbers of people lining the streets when one of the two football teams had been successful enough in the course of a season to parade their trophies atop a double-decker bus.

But even her home city didn’t take such things so seriously as to build a special street for parades. A colourful brochure giving the history of Carnaval in Rio told her that the Sambadrome Marquês de Sapucaí had been designed in 1984 by renowned architect Oscar Neimeyer. When Carnaval was not in season the purpose built grandstands and viewing boxes in the modified street were used for concerts by international performers. Marion recognized some of them as very big stars. Others had not become famous until after she had left Earth. This was Carnaval in 2016, when Brazil was hosting the football world cup later in the summer and Carnaval at the start of Lent was the overture to a festival fever that would last until September.

Marion was already impressed before she found out that Kristoph had reserved one of the air conditioned luxury boxes. These Camerote were like executive boxes at football stadiums. They were situated beneath the grandstands for ordinary citizens, and afforded the occupants a lot more breathing room as the seats filled. Other Camerotes were occupied by important local dignitaries and a famous Brazilian actress and her entourage. Below the Camerotes, Frisas were still exclusive but a little less special, occupied by groups of tourists or well off business people impressing clients. Whatever class, everyone was dressed in bright colours and ready to be thoroughly entertained.

The noise level was already considerable as the seats filled and crowds without tickets lined the pavements. There was a DJ playing recorded music above all the shouted conversations and the whistles and horns that seemed compulsory among the spectators.

Then the sound level rose even further. There was a roar of appreciation as the lead performers in the first of the Samba Schools swept into the Sambadrome under sweeping lights. Performers dressed in a riot of colour danced and displayed their costumes like birds of paradise. The consistent beat of the music leant a rhythm to the movement of their bodies.

After the dancers came a series of floats on the back of low loader trucks. These followed a theme of beach life. Scantily clad men and women danced among tissue paper sand dunes and cardboard palm trees with multicoloured parasols. On one float the undersea was the theme. The dancers had costumes emulating shoals of fish against shades of blue. After them came a troupe of dancers in fish costumes - the men in foam shark outfits and the women in very minimalist impressions of mermaids.

Scantily clad women featured in all of the performances. Even the most elaborate of costumes began with three small pieces of glittery, spangled or feathered fabric that stopped the woman from being completely naked. Carnaval was no place for anyone who was easily offended by the sight of flesh. Even so, Marion wondered briefly how such costumes went with the fact that the Carnaval preceded Lent in a deeply Catholic country.

It seemed not to matter if the appreciation of the audience was anything to go by!

One of the performances that struck her as most impressive to the eye involved a troupe of women, half of them with ebony skin made glossy with oil or make up, the other half pale skinned and made paler still with white cosmetics. The feathered costumes were made to look like peacocks, the pale women resembling incandescent albino peacocks. The contrast between the two not only reflected the beauty of the birds, but the ethnic diversity of Brazil, a country with both an indigenous and a European colonising ancestry.

Apart from the noise and the colours, and the lack of inhibition, what made Carnaval in Rio different from any parade along Lord Street, was the sheer length of tine it went on for. The first performers entered the Sambadrome at a little after nine o'clock in the evening and it went on all night, finishing about five o'clock with the dawn breaking over the city.

Marion was determined to enjoy it all. After all, she and Kristoph had stayed up from sunset to sunrise many times before and there had been balls on Ventura and HaeIlstrom, the more hedonistic allies of Gallifrey that had ended at dawn.

The Camerote service included a full buffet, but Marion and Kristoph chose to eschew the smoked salmon canapes for the food on sale for the general public. Street vendors climbed the stairways to sell hot bolos. These were a Rio variation on pasties, but with endless varieties of filling from excitingly spicy meat to exotic and sticky sweets. There were hot and cold drinks, too. Despite the night drawing in the Sambadrome was a warm place. The sheer energy of the Carnaval created warmth. Drinking liquids was essential. Non-alcoholic liquids were the usual thing, though delightful cocktails involving rum could be purchased too.

A hot drink with rum, vanilla and chocolate made Marion just a little sleepy as three o'clock drew around. She snuggled up close to Kristoph and closed her eyes, letting the music and noise overwhelm her while she let her imagination fill with the joyous dancing and fun.

She must have dozed a little, because in her imagination all the dancers dressed as birds had gained the ability to fly and were defying gravity all around the Sambadrome. She watched the aerial dance of human birds in myriad colours.

When she woke she thought for a moment that the dream was real. A huge float had a tall frame mounted upon it. Women in feathered costumes were standing high upon the frame so that they were level with the Camarotes that had looked down on most of the wonderful spectacle.

"Amazing," Marion whispered, applauding enthusiastically even though her appreciation was lost in the noise of all the other revellers. "Kristoph, isn’t this amazing. I hope they have some kind of safety line. If one of them fell..."

Kristoph didn't answer. She turned and saw that he wasn't looking at the parade. His attention was focussed on one of the Frisas below. There was a man sitting alone. He appeared to be interested in the parade, but just once he turned his head the other way and seemed to be looking their way. When he did, Kristoph turned his face towards the parade and appeared enthralled by it, but Marion wasn't sure that he was.

"What’s happening?" she asked him. "Who is that man?"

"What man?" Kristoph lied. "Nothing is going on. It’s quite all right. Are you enjoying the Carnaval?"

"Yes," Marion answered. "But..."

Kristoph signalled to one of the vendors and purchased a basket of small, sticky, warm chocolate bolo which served as a distraction for a little while. When Marion looked again the man was gone from the Frisa. Kristoph was fully interested in the float that was passing at that moment. Marion gave it her attention, too and let herself forget the strange moment when something other than Carnaval seemed to have become important.

The little sleep she had gave her a fresh impetus. The hours until dawn were not as difficult as she imagined they would be. The dawn itself added to the glory of the scene, the slanting rays of first sunlight bathing the Sambadrome and turning all of the colours brighter and more vivid than ever.

By the tine it was over the sky overhead was an even shade of blue without a single cloud in it and just a sliver of a crescent moon that had not yet set. The noise decreased very rapidly. The DJ was back, playing music and talking rapidly, but nobody was really taking any notice of him.

Marion and Kristoph descended the steps from their Camerote behind the actress and her male companion. As they reached the ground level, Marion turned and saw the man Kristoph had been interested in earlier. She started to say something, but a crowd of revellers coming from the tourist grandstand brushed along, coming between her and Kristoph and pushing her several yards along the Sambadrome before she was free of them.

When she got back to the place where she had last been with Kristoph he was gone. The actress was talking to a TV crew. Marion interrupted her, asking if she had seen where her husband was. In her tiredness and panic, even with the TARDIS translating for her, she got her pronouns confused and the Portuguese speaking actress thought the foreign woman was asking where HER husband was.

“He is in Sao Paolo with his mistress," the actress answered before turning back to the microphone. Marion was puzzled until she sorted out the answer and the confusion of pronouns but that didn’t explain where Kristoph was.

Or where the strange man was, for he had vanished, too.