McCormick had not learned the clones’ coded language, but a translation became visible on Marshall’s horrified face. He turned a shade of maroon, and his quivering gun hand pointed his pistol at McCormick’s head.

‘Nothing found on Floor Z,’ he snarled. ‘Nothing.’

McCormick did not move a muscle. Not even in his face. Especially not in his face.

‘Six minutes until half past, and the bomb is nowhere to be found. Gwen… better get to work now.’

Gwen Crossland shook her head.

‘I’ve told you before,’ she said with the slow voice of a playschool leader to a three-year-old. ‘Just like I told Nicholas when we had Ginelli. My work is not fast food. It takes time and precision. I can promise results that are accurate and trustworthy. But I cannot produce them at the speed that you and all the other impatient men want me to. If you have six minutes, my methods can’t help you with any reliable accuracy.’

She walked away from Marshall’s office, and her faint footsteps didn’t take long to leave McCormick’s earshot.

‘For the record,’ McCormick said to Marshall, ‘I don’t think six minutes is long enough either.’

‘You’d be amazed what I can do in six minutes,’ Marshall answered. ‘Gwen can spout whatever crap she wants about her precious methods, but I’ve got methods of my own.’

Marshall lowered his handgun just a little, and squeezed the trigger. A horrible bang sounded, and the bullet struck McCormick in the shinbone.

Chapter 26

10:25 p.m.

‘Guys!’ Kate screamed into the radio. ‘Talk to me! Where are you?’

Her eyesight was blurred with tears. The Floor D corridors were a mess of unfamiliar sights and the layout was barely navigable.

‘About half a corridor from the stairwell to Floor C,’ came Ewan’s voice. ‘If a miracle happens we can make it.’

Raj used to believe in miracles. I don’t think I ever did.

Her whole world was racing through her mind. The thought of her grandfather figure, trapped in a mystery location somewhere on the upper floors. Marshall’s computer not far above her. Mum and Dad in New London. The possibility of James still being alive. Her dead boyfriend. But more than anything else, the cigar-shaped detonator in her left hand.

She had dialled in the code the moment McCormick had revealed it, not trusting her panicked memory to remember it later. His secret weapon had been armed for what had felt like several hours, with the top cover closed to prevent her pressing the button by accident.

Kate didn’t know what the world would look like once she pressed the button. She only knew that the closer she was to Floor B when it happened, the easier it would be to reach Marshall’s computer while everyone was distracted.

‘Kate,’ came Alex’s voice, ‘we need a favour.’

‘What is it?’