I headed to the next vault. Works of art were piled round the edges. Even on the floor. Organised chaos. There were small sculptures lined up along the shelves and at the back was a large crate on its side. It was about the same dimensions as the crate Frederick had taken into the vaults on the trolley.

I ran to it. The crate was nailed shut. There was a small sliding lid within the top of the crate. It was fastened with a combination padlock. This had to be it.

If there was a bomb counting down inside this crate, I couldn’t risk smashing it open. Too big a jolt could set it off. I looked round the room. It was a cheap padlock, designed to put off nosey porters rather than really keep anyone out. There was a screwdriver on one of the shelves. I ran over to it and picked it up. Just a few well-placed taps should . . . And it was off.

I took a deep breath and slid back the lid.

I let out a cry. A crumpled, unconscious Robin was curled up inside. Strapped to him was a black box with a series of red flashing lights attached to blocks of C-4.

‘Vault four. I’ve found them. Robin and the bomb.’

Breaking the crate wasn’t an option. The motion could set it off. The only way to do it was climb in. I peered down. The timer was reading three minutes.

Jake and Geraint arrived at the vault.

‘Robin’s inside. The bomb is strapped to him. Three minutes. G-Force, give me the defuser.’ He reached over to me with it but Jake stopped him.

‘Forget it, I’m doing it.’

‘Jake, you won’t fit.’ I motioned towards the small opening. ‘Only I can.’ I took the defuser out of Geraint’s hands.

‘Now both of you go. Help with the evacuation.’

Geraint obliged, knocking over a picture on his way out. Jake didn’t move.

‘That fucker knew what he was doing. He knew it would have to be you.’ Jake slammed a hand against the wall.

‘Jake. Just get out of here. If it goes bad you know what you need to do.’

The benefit of having a partner who was also godfather to my only child meant one evening over several whiskies I had shown him exactly where on my laptop my post-mortem goodbye to my beloved daughter and husband were.

‘I must be able to do something, I must—’

‘Get the hell out of here. You know your job. Now do it. Speed up the evacuation. Save lives. I’ve got this.’ I stared him down.

He nodded. ‘Get our boy back.’ And ran out.

I climbed into the crate. My feet slowly touched the bottom, just up against Robin’s side. I gingerly lowered myself in, defuser clutched in one hand.