Peter Lawrence's hands are shaking. Not a vague, morning-after twitch, but a pronounced, relentless tremor. It is the only visible sign of the turmoil racking the otherwise restrained and dignified 62-year-old solicitor as he speaks about his daughter Claudia, who has been missing for 11 weeks.
Sitting in the quiet surroundings of the Middlethorpe Hall Hotel, York, neat in a grey suit, blue-striped shirt and yellow and blue tie, his voice remains modulated, calm and even. His words betray his desperation. "I hide it pretty well: I'm completely churned up inside even now talking to you. It feels as if there is a part of me missing. My phone is on constantly, for obvious reasons. Waiting for the call is the worst part."
That call, when it comes, is likely to confirm his worst fears; shatter all hope. The police believe Claudia Lawrence is dead. Her father clings to the dwindling hope that they are wrong.
The odds are not in his favour and they lengthen with each day that passes since Friday 20 March when Mr Lawrence went to his daughter's flat in Heworth, on the outskirts of York, and found her gone: disappeared without trace. Just two days before, Claudia, 35, who worked as a chef at York University, had been making plans to meet up with family and friends. No one has heard from her since.
What began as a routine missing person case has become the biggest operation by North Yorkshire Police in five years. More than 1,000 witness statements have been taken; hundreds of houses and vast swathes of countryside have been searched; innumerable posters have been distributed, repeated appeals broadcast on Crimewatch; a £10,000 reward offered. There have even been prayers from Dr John Sentamu, the Archbishop of York. They have not been answered. Police are treating her disappearance as suspected murder.
The past weeks have been "a living nightmare. There are obviously things that take your conscious mind off what has happened for a few minutes ... but it's always there. It is difficult to be in the public eye but it's my aim to make sure that Claudia's case stays in the public eye."
Through our interview, he struggles to retain his composure, as would any father in his place. He smiles only at memories of Claudia in happier times. "She was always quite adventurous... she was far more fearless at riding, jumping or anything else than her sister was." He chuckles at the memory of Claudia being left behind on the ground, as her horse sailed over a fence.
It is clear the two had a special bond. "I'd see her every week, sometimes two or three times.... I feel extremely privileged to be the father of a 35-year-old daughter who wanted to see her dad and to talk to her dad and chat about just about everything."
Their relationship survived the break-up of his marriage to Claudia's mother, Joan, 13 years ago. Until then, the family lived in the Yorkshire village of Old Malton. But around that time, Claudia left home and embarked on a string of jobs as a chef, moving to York four years ago. Her sister, Alexandria, 39, is married with two sons and lives in Derbyshire, where she is a director for a research company.
Claudia's mother and sister have mostly kept out of the spotlight. But in a show of family unity, they regrouped with Mr Lawrence last week to appear on the latest Crimewatch TV appeal for information.
Around 60 calls came in as a result, but there have been no fresh leads. The police appear to be out of ideas, and the family's only real hope rests on someone coming forward. Initially, the police appeared to focus on whether Claudia had been abducted on her route to work – she never turned up for her 6am shift on Thursday 19 March. But her usually "prolific" mobile phone texts had stopped shortly after 8pm the night before. Police assume she came to harm some time that evening. The only items missing from her house were a rucksack, her mobile phone, and her chef's whites. Her handbag, purse, passport and bank cards were left at home.
Police have no new leads: no CCTV; no forensic evidence. There has been no trace of the couple seen arguing on Melrosegate Bridge, on the route Ms Lawrence took to work, at around 5.35am on 19 March. A man spotted walking towards the back of Ms Lawrence's house 15 minutes later has yet to be found. And the identities of the man and woman seen arguing near the York University, at around 6am that day, also remain unknown. It is not even known whether they are the same couple spotted quarrelling 25 minutes earlier.
But Mr Lawrence has no criticism of the police investigation; none he is prepared to voice, anyway.
He was angered, however, by comments from Detective Superintendent Ray Galloway, who is leading the investigation, that Claudia had been involved in relationships "of complexity and mystery" which were kept secret from her friends and family. Mr Lawrence blames the remarks, made during the latest Crimewatch appeal, for the lurid speculation that his daughter led some sort of double life, with a string of sex partners.
"I was annoyed – and people did get the wrong impression. Claudia was very open about her life, and it is highly unlikely that we wouldn't know about a steady relationship. As a 35-year-old, single, good-looking young woman, I have no doubt that she had lots of male acquaintances that we didn't know anything about, and wouldn't expect to know anything about."
Struggling to maintain his composure, Mr Lawrence continues: "It makes me very angry indeed that there are people who obviously know something and aren't saying anything. They are the people that I keep getting at... on every possible occasion. I just don't see any excuse for them... protecting somebody is not an issue here..."
He pauses to calm himself. Suddenly he changes tack, casting his mind back to March, to the day he went to check on his daughter after worried friends had contacted him to say they hadn't heard from her.
"It hit me like a brick.... I went over, assuming that Claudia might be lying in the house not well or something. When I went in, the house was immaculate – her slippers were just inside the door as though she'd taken them off and put her boots on and walked out to work. She wasn't there, she hadn't been to work, wasn't in touch with anybody."
Until he gets evidence, however, Mr Lawrence will not accept that his daughter is dead: "I still have a feeling that Claudia is alive, and in the absence of evidence to the contrary, that's what keeps us going."
He will not give up "until this is resolved", adding: "Claudia, if you are reading this and you're able to do so, please get in touch with us – there's absolutely no reason not to, and we just need to know that you're safe."
Then the anxious father looks away again: silent, composed and still. Apart from the trembling of his hands.
Days turn to weeks: 'Every parent's worst nightmare'
18 March Last confirmed contact with Claudia Lawrence
19 March Claudia fails to turn up for work or meet friend Suzy Cooper at her local pub
20 March Worried she hasn't heard from her, Ms Cooper calls Claudia's father, Peter Lawrence. He calls the police
20-22 March Dozens of officers search for Claudia
23 March Mr Lawrence makes appeal for information at a news conference
25 March Police say Claudia may have come to harm after meeting someone she knew. More than 100 officers now involved in the search. CCTV footage of the chef's last known movements released
16 April Police reveal that, hours after she is thought to have disappeared, a couple was seen arguing along the route Claudia would normally take to work
17 April A body is found in the river Ouse in York. After several hours, Mr Lawrence is informed it is not Claudia
24 April Police announce they are treating the disappearance as possible murder
29 April In a police statement, Claudia's mother Joan pleads for help to find her daughter, describing the ordeal as "every parent's worst nightmare"
2 May Mr Lawrence sets up www.findclaudia.co.uk
15 May Police release CCTV images of two men near Claudia's home the morning after she was last seen
26 May Joan Lawrence speculates that her daughter may be abroad
2 June BBC1's Crimewatch
appeal generates 60 calls
5 June Police urge any man involved with Claudia to come forward
If you have any information, North Yorkshire Police 0845 6060247 Crimestoppers 0800 555111