Access to the darkroom, a former stable, was via an airlock set-up.

Two black blankets pegged on clotheslines. When Kate came out with the wet contact sheets, Bellaver's pet hypnotist was shining lights into Thomas Nolan's unseeing eyes.

Marcus Monserrat was a venerable, bowed gent with leg-braces and crutches, deeply suntanned or part-Asian, sporting a neatly trimmed white beard. A brain specialist, he'd returned from a sojourn in Tibet with a supposed mastery of ancient mesmeric techniques.

She remembered the '20s and '30s craze for going to Tibet and acquiring the power to cloud men's minds. The Disappearing Diplomat, James Hilton's biography of Hugh Conway, inspired a lost generation of fatheads to freeze their extremities off trudging up snowy Himalayas in search of Shangri-La, Shambhala or K'un-L'un. Kent Allard, a flier she'd known during the First World War, was one of the few who came back. With Tibet occupied by Red China, would-be mystics favoured the Maharishis of India. She understood serious dark postulants had moved on to a new continent. They hung about Ayers Rock soliciting Aboriginal shamen for the secret of killing via shouting or bone-pointing, as if there were a crying need for cleverer ways of murdering people.

For Monserrat, supernatural powers hadn't meant material wealth. He didn't seem to have set out to be an ascetic. Once a prosperous Harley Street neurologist, he now had cards up in newsagents' in Marylebone High Street. His clientele ran to cash customers who wanted to give up smoking or biting their nails. Kate didn't know how Monserrat came to be on B Division's books. He must have helped on previous cases. This wasn't the first time a witness to vampire crime had been fascinated into keeping schtumm. Clearing the fog would be a useful trick. If it wasn't arrant quackery. Which, in Kate's opinion, it was.

Nolan sat limply in his egg-chair, hands in his lap. Monserrat had at least got him to stop taking imaginary snaps. The subject was awake, but unresponsive.

Hypnotism had progressed from 'watch the watch'. An array of multi-coloured lights mounted on one of Nolan's own tripods flashed in arcane sequence. With 'A Whiter Shade of Pale' leaking in from the waiting room, the studio was like a duff discotheque. Kate wished they'd change the record. After hours of Procul Harem, she'd have taken Any Old Iron' or 'I Was in Kaiser Bill's Bat-Staffel'. Or, for preference, 'The Sound of Silence'.

Bellaver stood to one side, with Griffin and WPC Rogers  -  who'd brought Monserrat to Pottery Lane  -  and a slim, white-haired, elderly woman. Monserrat's wife was a vampire, which meant she chose to seem the age she looked  -  probably to match her husband. Kate had come across that before and was not one to criticise whatever people did to make relationships work. But. Mrs Monserrat was bright-eyed and a little creepy. She stared hungrily, fangs out, at the young man under her husband's 'fluence. Kate didn't need a package holiday in India to know what she was thinking. It was a good job Enoch Powell wasn't here: the expression on Mrs Monserrat's face was exactly what vampire-haters were afraid of.

Monserrat was getting no response from Nolan.

Bellaver, bored, came over to look at the pictures.

Any joy?' he asked.

'Fifteen rolls of it,' Kate said. 'Lin Tang is making prints of every exposure, but here are the contact sheets. The Fevre Dream stuff could go to the News of the Screws. It's what you'd expect. Rich, beautiful, famous, horrible people having a knees-up.'

'So you don't get invited to Syrie Van Epp's parties?'

'Please  -  if I ever fall in with that mob, stake me. They're the worst sort of useless.'

'Any pictures of Carol?'

'Lots. At the party, and... afterwards.'

'How afterwards?'

'In a cab, I think. And in Maryon Park.'

Bellaver was reminded of another avenue of inquiry. 'Griffin, have we rousted out last night's taxi drivers?'

'Yes, Super. No luck yet, but if Carol Thatcher went from the boat to the park in the small hours the cabbie should be traceable.'

'If it's easy, it should have been done by now, lad.'

'Yes, Super,' said Griffin, looking at his pointy shoes.

'She must have got to the park just before dawn,' said Kate. 'There are twilight photos. Sun-up is  -  what?  -  four, four-thirty, this time of year?'

Kate laid out the contact sheets on an artist's table. An overhead light brought out the sheen of the photographic paper. Columns of glistening images, in black and white and colour. She gave Bellaver a magnifying glass.

'What's that pong?' the policeman asked.

'Chemicals,' she said. 'No need to call the Drug Squad.'

The spell in the darkroom with Lin Tang had made her slightly light-headed. Lack of blood, exposure to sunlight and general irritability were working on her too. She wasn't seeing something.

She arranged the photographs in chronological order, trying to find a story in them. She had to go against instincts and read down columns rather than across. Even that might be a mistake. The sheets read deceptively like a Japanese-Italian photo-comic, but Nolan didn't always catch relevant moments. He hadn't known he was compiling a record of the last hours of Carol Thatcher's life. More false leads than true clues.

'Let's play Spot the Ball,' said Bellaver, peering through the glass. 'Professor, can you haul Golden Boy over here?'

Monserrat commanded Nolan to get up and go to the table. The hypnotist had more difficulty crossing the studio than his subject. His wife had to help. Annoyed, he tried to shrug off her firm arm-grip.

Blankly, Nolan stood at the table.

'Does this ring any bells?' the Super asked.

'He only hears my voice,' said Monserrat, lisping softly. 'Look at the pictures, Thomas. At your pictures.'

Nolan hung his head and ran his fingers over the wet sheets, as if they were secret messages in Braille.

The photographer mumbled. Snatches of lyrics. Songs from the party?

The most interesting thing about Nolan's pictures was that vampires showed up in them. Edwina can't have sprinkled silver talcum on everyone. Lin Tang said Nolan was conducting experiments with chemical processes and new makes of fast film. It was an obsession: finding a way of taking good likenesses of vampires. Kodak had marketed a film for the undead in the 1950s, Kate remembered. Results were iffy. Nolan wasn't fully there yet, and maybe it couldn't be done, but vampires at the party weren't invisible. Some were negative images, some see-through and some sketchy or featureless  -  but they were captured on film. Bellaver was interested, too. Taking mug-shots of vampires was a challenge, let alone using photographs in evidence. Some were incautious about public behaviour, since revealing pictures would not show up in the scandal sheets. If Nolan's work continued, contingent upon him getting his wits back, habits would have to change. Was Carol's death incidental? Could the real purpose of the crime committed in Maryon Park be to stop Nolan developing the art of vampire photography?

'Recognise any of these spooks?' Bellaver asked her.

'Surprisingly, yes,' Kate admitted. 'That's Herbert von Krolock in the lime-green shorts and t-shirt, snogging that actor from A Kind of Bleeding. What's his name, Alan Bates? The pretty boy is Paul Durward, an elder who sings a bit. I don't know the warm blonde with the cleavage who's all over him. This one is unmistakable, though I can't name any of his coterie...'

She tapped a picture of a grey man. His hair was more bouffant than when she'd last seen him. He kept 'with it' in a wide-collared dayglo suit and frilly-fronted, floppy-cuffed orange shirt. But his face was congealed death. Nolan's process showed up patches of rot on his cheeks and forehead which might not be visible to the naked eye.

'Caleb Croft,' said Bellaver.

Kate shuddered at the name. If ever a vampire were a monster.

Professor Croft was flanked by vampires in matching monk-hoods. Their faces were indistinct, hollows in the cowls. One wore a black-and-white St Bartolph's scarf. This year, everyone was seeking a guru. The thought of Croft getting his teeth or  -  worse  -  mind-hooks into young people, warm or vampire, was appalling. That scarf caught her attention. Having noticed it once, she saw it over and over. Not always on the same person.

'These pictures,' Monserrat said to Nolan. 'They are not last night, they are now. Tell us what's happening.'

'I'm on a boat,' said Nolan. 'It's a trip. A far-out trip.'

'Is there a girl?' asked the hypnotist.

Even deep under the fluence, Nolan smiled. 'Girl. Girls.'

Nolan photographed any woman who crossed his viewfinder. He even took a few exposures of Lin Tang, who had  -  somehow  -  changed her outfit two or three times during the party. Kate recognised fabulous birds from films, telly and the rotogravure. Julie Christie, Catherine Cornelius, Sandie Shaw, Moira Kent, Anita Pallenberg, Fontaine Khaled, Julie Ege, Ayesha Brough. One shot caught actress-model-singers Gillian Hills and Jane Birkin, giggling conspiratorially, regarding the camera with a gleam at once promising and predatory. Penelope Churchward, who moved in these circles, wasn't at this do; Kate thought Penny was in New York just now, keeping secrets.

'One girl,' said Monserrat. 'Carol.'

In the party photographs, Carol went from extra  -  cut off at the sides of pictures  -  to leading role. She had caught Nolan's attention: a whole sheet consisted of shots of her at the party, sometimes chatting or dancing with others, but mostly on her own, smiling or puzzled. Why her, of all the girls there? Did Nolan have an instinct for spotting the soon-to-die? If so, Kate should be wary since he'd snapped off a reel on her too. Was Carol flattered that the cyclops singled her out? Or spooked? For a model, but Kate thought Carol seemed uncomfortable at being photographed. That could have been pathetic fallacy, an awareness of the tragic ending shadowing innocent looks with spurious meaning. Timothy Lea was in a few early shots, stuffing his gob with canapes, then got lost in the crowd. Had he been got rid of? Lin Tang, Edwina and the wrestler  -  Milton  -  were in the pictures. Might they have hustled Timmy out of the way to give Nolan a clear run at the girl?

Now, Nolan saw the ghostface girl and mumbled.

'Carol,' he said.

'Is he remembering?' asked Bellaver.

'She's a white flame,' said Nolan.

Beyond the party photos, they came to shots taken inside the taxi Carol had been in sometime between the boat and the park. The Daughter of the Dragon said Nolan took off without her. Kate intuited that Lin Tang was still irritated by that escape, and would have been even if it hadn't ended in murder.

In the cab, Carol wore the St Bartolph's scarf. Nolan used high-contrast black-and-white film. Other people were in the back of the taxi, but Nolan was working close, shooting Carol's face whenever light came through the windows. Shadows chopped across the pictures. These exposures would be blown up. Perhaps a hand  -  with one of those fabled, distinctive rings  -  might be resting on her knee in one shot? Or an array of blobs would coalesce into a recognisable culprit? Kate thought they couldn't be that lucky.

Nolan was interested in Carol's face. Not some vampire licking his lips in the shadows.

Even hypnotised, he was drawn to her. He put fingerprints on the sticky pictures.

Having seen Carol dead, Kate was struck by how alive she'd been. She understood why so many wanted to get close. Timmy Lea was lost without her. Not that he'd have been able to hang on in her life if she were taken up by Nolan's circle. She was, or seemed in stills, luminous. Or perhaps Kate was projecting on a blank, dead slate.

The last contact sheet was a roll of colour, taken in Maryon Park in the blue light of pre-dawn. Magic hour. Carol, trailing that scarf, walked a path towards the trees, looking over her shoulder, smiling. At Nolan, of course, but also at others. Shadows clustered on the ground.

Kate couldn't help but hope Croft was there. She'd waited decades for him to be caught red-mouthed. It was as likely Carol had snatched the scarf from a student and run off with it as a trophy. Why should she latch onto a mouldy professor and his inky followers? So many more exciting, dazzling, dangerous persons were on hand.

'That scarf,' she whispered to Bellaver. 'Was it found near the body?'

The Super checked his notebook. 'Nope. Unless Griffin missed it.'

'There was no scarf,' confirmed Rogers, defending the sergeant.

Nolan was shaking now, quite alarmingly.

'What are you seeing, Thomas?' Monserrat asked.

'Red,' he said. 'Sunlight, like blood. No. Blood, like sunlight.'

Ideally, the final photograph would have shown Carol in a clinch with a gore-smeared monster  -  his (or her) face captured perfectly in the light of dawn, fanged maw open wide and guilty. Instead, it was an empty frame, or a seemingly empty frame: a blur of bushes and grass and jagged shadow, and Carol's torn-open neck and shoulder.

'Who's here?' Kate asked, pointing at the photograph. Monserrat passed on her question. 'Who's with Carol?'

'Eyes,' he said. 'Sunrise eyes. Burning blind.'

'He doesn't know any more,' Kate told Bellaver. 'If you push too far, he'll break.'

'Who is in this picture?' Monserrat insisted.

'Can't say. Eyes, ice, aieee!'

Nolan's mouth was full of white froth. Some leaked onto the photos.

'Bring him out of it,' said Kate to Monserrat. 'Or he'll shrink inside his head. You'll never get him back.'

Monserrat wasn't taking instructions from her, but Bellaver gave him the nod.

'Wake up, Thomas,' he said, 'in three-two-one...'

Monserrat snapped his fingers and Nolan collapsed. A Thunderbirds puppet, suddenly unstrung. Despite the hypnotist's order, the photographer hadn't woken up. He'd gone to sleep, which couldn't be good. WPC Rogers caught Nolan easily and heaved his deadweight upright. He came round, then found himself in the grips of a uniformed vampire and took fright.

'What?'

Rogers patted him down as if he were a Saturday night drunk and handed him to Edwina. The make-up girl led Nolan away, promising a nice cup of tea and a suggestive biscuit. Thomas Nolan was insulated like a child. He had people to nanny him after his tantrums and coddle him when he was showing off.

Bellaver looked at the disarrayed photographs and shrugged. 'I'd say "every little helps", but it doesn't, does it?'

Kate had to admit he was right. She took the magnifying glass and twiddled with it.

She kept going over the contact sheets. There was something she wasn't seeing. Or something she was seeing she shouldn't. A notion fluttered, demanding attention  -  but when she looked again, through the glass, at particular pictures, she couldn't see what it was.

It was mid-evening, still light out but cool. The sun that had risen on Carol Thatcher's death was going down. Kate, bone-tired and headache-hammered in daytime, felt senses sharpening with the coming of night. With dark-adapted eyes, she might see more.

Edwina came back then. She had corralled someone else to make the tea.

'Phone call,' she said. 'For the Superintendent.'

'Probably the Chief Constable, dishing out a bollocking,' Bellaver said to Kate. 'He doesn't like being bothered by your lot  -  journalists  -  on Sundays, or any other time. And he likes to spread the joy.'

Bellaver went to the waiting room.

Kate was intrigued by Edwina's healthy throat. She was a very English girl  -  almost prim  -  with an attractive little croak in her voice.

'If you're thinking of biting me, luvvy, you can shove off,' she said.

Kate shut her mouth and  -  she was sure  -  went red. She'd be looking like a pillar-box again. She didn't drink from other women, except in the most antiseptic, unromantic of circumstances. The possibility, even, only occurred to her during dry spells. She supposed she was still a Victorian. Not that the Victorian times she remembered were any less omnisexually adventurous than the swinging '60s; people were just better about keeping quiet.

Bellaver came back, obviously bearing bad news.

'The Chief Constable?'

'Worse. George Dixon. There's been another one. A dead girl. Another white-lips. He's not going to stop at that, is he? The bastard. It's a flaming spree.'