‘Immediately. We have a protocol for security issues. The pupils were asked to remain in their classrooms and not to move out of them. We’ve spent a small fortune on CCTV equipment and have recently employed a registered security guard. He and the caretaker, plus myself and my deputy, did a thorough search, and your people are now checking the school and the grounds again.’

‘We need to see that CCTV footage,’ said Jackman. ‘Immediately.’

Marie knew that the footage was their best chance of discovering what had happened, but even so, she didn’t hold out much hope.

‘Come with me.’ Jonathan Lewis went to the door. ‘My secretary is already checking through it with one of your officers.’

In the general office, they found PC Simon Laker with the school secretary, their eyes fixed on a screen.

‘We’ve located him twice, sir,’ said Simon. ‘On both occasions he was walking alone along a busy corridor, then — nothing. There are a lot of areas covered by the surveillance cameras — the exits and entrances, most of the corridors and all the classrooms and halls. It’ll take a while, but we’ll keep at it.’

Marie could sense impatience rolling off Jackman in waves.

‘Okay, do that,’ he said to Simon, and turned back to Lewis. ‘Have you had anyone unauthorised come into the school today? Deliveries? Maintenance men? Anyone unexpected?’

‘No, no.’ He shook his head. ‘And there are no supply teachers here at present, it’s just my regular teachers and admin and catering staff, and our permanent caretaker and groundsman.’

‘No extra ancillaries or helpers at all?’ said Marie.

Lewis frowned. ‘Certainly no one new, although we do have two student teachers from the local university observing the classes, and our PE teacher, Mr Fawcett, has a scout for one of the county football teams in this week. But they’re all carefully vetted and checked, I assure you, as is Mr Edwards. He’s been with us, two days a week, for almost a month now, from the Wildlife Conservation Society. He’s been giving talks on conservation science and wildlife management. A lot of the youngsters are very interested in helping to save wildlife.’

‘I’d like to talk to all of these people, Mr Lewis, and can I just ask—’

‘Mr Lewis, sir? Sorry to interrupt, but it’s important.’

They all looked round to see a plump woman in a pleated skirt and floral print blouse standing in the doorway. ‘One of my class recalls seeing Davy, sir.’

‘Which child was that, Miss Lloyd?’ the head asked.

‘Lindy Hopson, sir. She’s a very reliable girl. She saw him about five minutes after the English class finished. He was talking to Mr Edwards outside the biology lab. She thinks they went inside, because when she looked back, they were gone.’

Marie glanced at Jackman, who took the image of Spiller from his pocket. He thrust it out towards the headmaster.