Ron Pulaski’s find forty minutes ago was that the Inwood marble trace Sachs had collected was unique to this portion of Manhattan and that explosives permits had been issued to the general contractor building a new wing of the Upper Manhattan Medical Center. Other trace – the industrial cleanser quats and the adhesive that could be used in bandages – also suggested that he’d been inside the hospital to plan his attack on victim number two.

Sachs had hardly expected to actually interrupt him.

Breathing deeply, she paused at the fire door, pushed it open, dropping into a combat shooting pose. Swiveling back and forth. This was the morgue level; there were four employees in scrubs chatting and sipping coffee, standing beside two covered gurneys.

They turned, saw the gun, then Sachs, and went wide-eyed, frozen.

She held up her shield. ‘White male in dark coat. About six feet, stocking cap or mask. Slim build. Come by here?’

‘No.’

‘How long you been here?’

‘Ten, fifteen min—’

‘Get inside and lock the door.’

One attendant started to push the gurney through the door. Sachs called, ‘Only the live ones.’

Back to the dim stairwell. Down more stairs. She hit the lowest sub-basement. He had to’ve come here.

Go.

Fast.

When you move, they can’t getcha …

She pushed through the door, swinging the muzzle right and left.

This floor was deserted, devoted mostly to infrastructure and storerooms, it seemed.

She kept swiveling, right, left. Because in the back of her mind was the persistent thought that maybe this wasn’t an escape at all. Maybe it was a trap. Maybe he was hiding here to kill a pursuer.

She remembered the line from the book Serial Cities, about Rhyme:

Experts in law enforcement universally voice the opinion of Lincoln Rhyme that his greatest skill was his ability to anticipate what the criminals he’s pursuing will do next.

Maybe Unsub 11-5 was anticipating too.

Terry Dobyns had also suggested that he might target the police.

As her eyes oriented to the dimness, she examined the corridor. He couldn’t go to the left – that was a dead end. To the right, a sign announced, was the tunnel that led to the doctors’ office building.

He could either escape that way … or lie in wait for her.

But nothing to do other than go for it.

Knuckle time …

She started in that direction.

Suddenly a figure appeared in front of her, coming down the tunnel. She paused, plastered herself against the wall, aiming her weapon high but in the general direction of the man.

‘Hey,’ he called. ‘I can see you there. You police?’

A large African American dressed in a black rent-a-cop security outfit – more intimidating than an NYPD uniform – walked closer. ‘I can see you! Officer.’

She whispered harshly, ‘Come here! Get under cover. We’ve got a perp somewhere.’

He joined her and they both pressed against the wall.

‘Amelia.’