Heart tapping, breath loud through the mask, Sachs peered in the direction of the hiss, which was now a piercing sound. She moved up to the wall on the other side of which was the access chamber where he’d drilled the hole in the pipe. She glanced in fast, low, in case he was aiming head or chest toward the doorway. All she could see in the one-second look was mist roiling in shifting curtains, pastel colors, like the northern lights. It was backlit by a muted white lamp – maybe one the unsub had set up to illuminate his drilling. The hypnotic swirls, beautiful, would be from the particulates of streaming water flowing from the pipe.

Sachs was reluctant to do a typical one-person dynamic entry, look high, go in low, two pounds’ pressure on a three-pound trigger. Shoot, shoot, shoot.

Not here. She knew she had to take him alive. He wasn’t operating on his own, not with a plan this elaborate. They needed to collar his co-conspirators, too.

Also, any weapons discharges might mean she’d end up shooting herself; the pipe and the concrete surfaces of the tunnel would easily send the copper jacketed slugs and fragments zipping in unpredictable directions.

Not to mention what a 9mm parabellum round would do to a vial containing the deadliest toxin on earth.

Closer, closer.

Peering into the wall of mist, looking for shadows moving, shadows in position to fire a weapon. Shadows charging out with a hypodermic syringe loaded with propofol.

For his final skin art session.

But nothing other than the shimmering particles of water vapor, refracting light so beautifully.

Into the chamber, she told herself. Now.

The cloud rolled closer and withdrew, surely from the breeze created by the stream of water. Good cover, she thought. Like a smoke screen. Sachs gripped the Glock and, with her feet in a perpendicular shooting position, not parallel, to minimize his target area, she moved fast into the room.

A mistake, she realized quickly.

The spray was much thicker inside and soaked the filter of the mask. She couldn’t breathe. A moment’s debate. Without the protection, she’d be susceptible to the botulinum toxin. With it, she’d pass out from lack of air.

No choice. Off came the mask and she flung it behind her, inhaling the damp air, which, she hoped, contained only New York city drinking water and not poison powerful enough to kill her in all of five seconds.

Breathing, breathing …

But so far, no symptoms. Or bullets.

She continued forward, swinging the gun from side to side. To her right she could see the dark form of the massive pipe; the puncture was about fifteen feet in front of her, she guessed; from a vague image of a thin white line – the stream of water – shooting up to the left and hitting the far wall about ten feet off the ground. The hiss grew louder with every step.