They came to the stairs at the end of the hall and went down past the seated statue of Charles Darwin. In front of them now was the fossilized diplodocus, stretching half the length of the big open space. Darkness clung to the walls. There were only a couple of small candles burning. They were precious and the museum kids didn’t like to light them unless they absolutely had to. When it came to lockdown they’d be snuffed out. There was still some brightness showing at the tall, church-like windows at the front of the museum; it was slowly fading, though, the blue deepening.

‘We’d better hurry,’ said Jibber-jabber.

‘Like you have to tell me that.’

Two thirteen-year-olds came out of the blue zone. They were chatting to each other and they laughed at something, the sound of it filling the hall. The thirteen-year-olds were the worst for teasing, so, while Jibber-jabber was comforted by their presence, he didn’t want to risk asking them to escort him like a toddler.

He hurried over to the toilets at the back of the hall near the base of the stairs. Ella trotted beside him. She stopped when they came to the door of the gents.

‘I’m not coming in there with you,’ she said.

‘I’ll be in a cubicle.’

‘Yeah, but you’ll make noise and smells. I can’t even go if I think someone can hear me.’

‘All right,’ said Jibber-jabber. ‘But you won’t run away, will you?’

‘No.’

‘Can I prop this outside door open so that I can, like, call out to you?’

‘I won’t go anywhere,’ Ella snapped. ‘I’m staying here until you come out. I don’t want you shouting out to me as you do a poo.’

‘I’ll just prop it a little way.’ There was a wooden wedge nearby and Jibber-jabber kicked it under the outer door so that it was held open just wide enough for him to slip inside.

‘Will you come in with me to check it’s all right?’ he asked when he was done.

‘If you want.’

The two of them went in and Jibber-jabber quickly shone his torch around.

‘There’s nothing,’ said Ella, who seemed keen to get out as quickly as possible. Jibber-jabber walked over to the shelf by the sinks where there was always a tea light in a holder and some matches. You could light it when you were in there, but had to blow it out before you left.

By the time he’d got the candle going Ella had gone. He shouted out.

‘Can you hear me, Ella?’

He heard her voice coming back from outside, sounding small and distant.

‘Hurry up!’