She never did, and in the morning they’d organized a proper search. All that they’d found was this small patch – not much bigger than a 1p piece – and even then they couldn’t be sure it had anything to do with Samira.

Maxie watched as Gordy went down on his hands and knees and started scraping whatever it was into a small plastic envelope. He was still feeling very guilty from last night and Justin had taken over from Maxie giving him a hard time about it.

‘If you want to be in charge of the labs while Einstein’s away,’ he said, ‘you’ve got to be more responsible.’

‘It’s not my bloody fault,’ Gordy muttered. ‘Anything could have happened to her.’

Now Gordy turned on Maxie.

‘What do you think happened then?’ he snapped. ‘I thought you’d cleared all the sickos out of the museum. Or maybe you’re not as great as you make out.’

For a brief moment Maxie considered laying into Gordy, really letting rip. But she held back. He was scared and turning his guilt on someone else. It took an effort, but she was going to be bigger than him and let it go. Instead she nodded to Justin to follow her and walked through to the lab next door, which was unoccupied.

She looked back through the glass wall at the lab they’d left. There were a few kids there, too distracted to work, standing in small groups, talking excitedly. She closed the door.

‘What we talked about the other day. About one of your lot having a problem. A saboteur, a traitor – I don’t know what you want to call it … What have you done about it?’ she asked Justin.

Justin looked a little shifty and unsure of himself. ‘I don’t want to start a panic,’ he murmured.

‘You don’t think Samira disappearing is going to maybe do that for you?’

Justin walked Maxie over to the windows, where they could look down to the main floor of the Darwin Centre eight storeys below. The great curving white wall of the Cocoon that filled the huge space was shining in the sunlight.

‘I’m sorry,’ he said. ‘I should have done something. I was just hoping, I don’t know, that you’d find something in your clean-up. I don’t want it to be one of us. I want it to be safe here again.’

‘We can sort it,’ said Maxie. ‘But you have to tell people that someone can’t be trusted. No one should be going anywhere alone at the moment.’

‘Will you help me set up a committee?’ he asked.

Maxie tried not to laugh. She wasn’t quite used to Justin’s adult way of speaking. ‘A committee?’