One step at a time. Shoot the bites with the 105-millimeter quartz lens. Standard color film first, then get out the filters and start on the UV. After that, take your alginate impressions.

As I bend and flip the latches on my case, I feel like I’m moving at half speed. A dozen pairs of eyes are watching me, and their gazes seem to be interfering with my nerve impulses. Sean will notice my awkwardness, but maybe no one else will. “It’s the same mouth,” I say softly.

“What?” asks Agent Kaiser.

“Same killer. He’s got slightly pegged lateral incisors. I see it on the chest bites. That’s not conclusive. I’m just saying my preliminary assessment.”

“Right. Of course. You sure you don’t need some help?”

What the hell am I saying? Of course it’s the same guy. Everybody in this room knows that. I’m just here to document and preserve the evidence to the highest possible degree of accuracy -

I’m opening the wrong case. I need my camera, not my impression kit. Jesus, keep it together. But I can’t. As I bend farther down to open my camera case, a wave of dizziness nearly tips me onto the floor. I retrieve the camera, straighten up, switch it on, then realize I’ve forgotten to set up my tripod.

And then it happens.

In three seconds I go from mild anxiety to hyperventilation, like an old lady about to faint in church. Which is unbelievable. I can breathe more efficiently than 99 percent of the human population. When I’m not working as an odontologist, I’m a free diver, a world-class competitor in a sport whose participants commonly dive to three hundred feet using only the air trapped in their lungs. Some people call free diving competitive suicide, and there’s some truth to that. I can lie on the bottom of a swimming pool with a weight belt for over six minutes without air, a feat that would kill most people. Yet now-standing at sea level in the kitchen of a ritzy town house-I can’t even drink from the ocean of oxygen that surrounds me.