Picking up his mobile he dialled the number of the New York clinic where Anouk was being kept. Elena, who’d accompanied the girl to Manhattan, had called him from there. He just had to press recall to get the main office. He introduced himself as Dr Schwartz in the hope of being connected quicker as a potential colleague, but it took a good quarter of an hour before he got the doctor in charge, Dr Silva, on the line.

‘Anouk is not who we think she is,’ he explained to the elderly gentleman who sounded as if he had a cold.

‘What are you saying?’ Silva asked.

Martin was pacing in circles around his kitchen, far too agitated to keep still.

‘She’s not traumatised, at least not to the extent that it appears.’

‘Not traumatised?’ Silva was incensed. ‘First the girl was raped and then abducted.’

Martin paused briefly, to order his thoughts and avoid sounding like one of the befuddled patients his colleague treated.

‘Have you ever worked with highly intelligent children, doctor?’ he asked Silva. ‘You know what happens when they’re not stretched. Children who are that bright start displaying behavioural problems. A few go silent, others stop eating and sink into depression, and others become loud, aggressive and even violent sometimes. To other people or themselves.’

‘I’m still listening,’ Dr Silva said when Martin paused.

‘What I’m trying to say is that I believe Anouk suffered from understimulation stress for months. Of course she was badly traumatised by the serious abuse. But that wasn’t what stopped her from talking or made her scratch her skin.’

‘So what was it?’ Silva asked.

‘To put it crudely, Anouk got bored.’

‘What?’

‘Being locked up on a ship, first in a windowless dungeon, then on an isolation ward, without any opportunity for normal development. Even mentally healthy people would find it hard to cope with that. So how must a hyperactive, highly intelligent child feel? Scratching herself was an expression of her lack of stimulation.’

‘What other evidence do you have?’

‘The code,’ Martin replied. ‘Anouk couldn’t tolerate sitting still any more or continue to obey Shahla’s instruction not to talk to anyone. That’s why she made up a game and communicated to me in a secret language. A highly intelligent game. Anouk’s code is difficult to decrypt. You have to be a memory champion like her to master it.

‘How does this secret language work?’ Silva sounded faintly irritated. Martin could understand that. He’d have reacted just as sceptically if a supposed colleague had rung out of the blue from abroad to give him a lecture.

‘Have you also noticed that Anouk never answers the first three questions? Not in any conversation?’ he asked.