The layout of the big cat house was linear, with an entrance at either end. The door leading to the offices and zookeeper back-channels was at the other end of the room from the entrance I had used. Naturally. Circumstances never conspire to deposit me near the door I need. As I approached the door, I saw that it was also standing slightly open. Not enough to be obvious from a distance, but enough that it was obvious someone had been through very recently, and in a hurry.

Stealth was abandoned again as I jogged for the open door. The big cats matched my stride, although they were stopped by the edges of their enclosure, and snarled in obvious frustration as I went through the open door and stepped into the narrow white hallway of the backstage area of the big cat house.

There was blood on the floor.

Not much—just a few drops, small enough that they could almost have been dismissed as runoff from feeding the cats. Except that the big cats didn’t get live prey, no matter how much they wanted it, and nothing dead bleeds like a living body. This blood was bright red, almost artificial-looking, with none of the watery clarity of blood that came from pre-butchered meat.

The halls were silent. I stopped long enough to draw my gun and continued forward, listening for any sign that I was not alone. The blood trail led deeper, curving away from the offices and into the channel that was used to carry food to the big cats. I followed it, trying to focus on the entire area, and not just on the question that those bright drops of blood forced me to keep asking. Who was bleeding? Shelby, or someone else? How badly were they hurt? There wasn’t enough blood to be fatal, but that didn’t have to mean anything. There are a lot of ways to keep blood from hitting the ground.

The trail led into one of the feeding pens. I hesitated only long enough to be sure that the channel connecting it to the cage on the other side was closed. Then I unlatched the door and stepped inside.

It was a small, concrete space reminiscent of the zoos of old, the ones where the animals slept on bare stone and were little more than prisoners of man’s eternal war against the natural world. The walls, floor, and ceiling were all designed to be easily hosed down, and there was a drain in the middle of the room, making it clear that the hosing happened on a fairly regular basis. In addition to the entrance and the broad, portcullis-like barrier that separated the feeding room from the open enclosures, there was a narrow, solid metal door set deep into one wall. In case something went wrong during a feeding, the keeper was to retreat into the tiny built-in “panic room,” giving time for the other keepers to run for help.

The blood trail led to the panic room door.

Cautiously, I approached the closed door. When I was close enough, I whispered, “Shelby? Are you in there?”

“Alex?” There was no mistaking the relief, or the pain, in her voice. “Is that really you?”

“If not, I was replaced so long ago that it doesn’t make any functional difference,” I said, which may not have been the most reassuring answer possible. I was too worried about her to think straight. “Can you open the door?”

She laughed a little, unsteadily. “No. It’s not meant to be opened from the inside. I wasn’t thinking too clearly when I ran in here.”

“Okay. Can I open the door, or will you shoot me if I try?”

“Are you sure you’re Alex?”

“Believe me, no one else is going to claim my family.”

This time, her laughter was a little more sincere. “All right. Yes, you can open the door.”

“Thank you.” After one last glance back to make sure that no one was sneaking up on me, I holstered my gun and opened the panic room door. Shelby, who had been crammed into the small space with little room to move, or even turn around, tumbled out. I managed to catch her before she could hit the floor. She cried out—a small sound, quickly swallowed, but that was enough to tell me that the blood was definitely hers. “Shelby?”

“It’s nothing.” She paused before laughing unsteadily. “All right, it’s not nothing, but it’s not that bad. Let me up.”

I let go of her, and she straightened, pulling away from me. The motion revealed the blood soaking into her khaki top, turning it a plummy purple. “Shelby . . .”

“No, really, it’s nothing. Look.” She pulled up the bottom of her shirt, revealing a cut that slashed across her ribs, deep enough that it was going to need stitches. It was surrounded by a thick crust of dried blood. “Hurts like nobody’s business, but it’s not going to kill me.”

“What happened?”

“I barely believe it, and I’m the one who got stabbed,” she said, pulling her shirt back down. She shook her head slowly, confusion written plainly across her face. “It was Lloyd.”

“Lloyd? The security guard?”

Shelby nodded. “The same. He saw me checking the bushes outside the cat house. Came over to ask what I was doing here when the zoo was closed, and I said I’d dropped my wallet in the bushes the day before, and that I was trying to find it. He offered to take me back to the office to check the lost and found, and I would have gone with him so that I didn’t seem suspicious, but . . .” Her voice trailed off.

“But what?” I prompted.

“But when he saw that I was wearing glasses, his whole face changed. He didn’t look like Lloyd. He looked like a stranger—an angry stranger, who wanted to hurt me. He asked whether I’d always worn glasses, and I said no, they were new. I should have pretended, I should have said I wore contacts for work, but I wasn’t thinking. I was just reacting. As soon as I said that . . .” Shelby paused again before looking up, meeting my eyes, and saying, “He said he wasn’t going to let me stop him. That he’d always liked me, but that he couldn’t let that change anything. And then he drew a knife. On me!”

“What kind of knife?”

“A stupid big one, that’s what kind of knife,” snapped Shelby, looking annoyed. “Does it matter what kind of knife? He pulled it out of his coat and he stabbed at me in broad daylight, where anybody could have seen.”

“That means he wasn’t worried about getting caught,” I said. “That’s a bad sign.”

“You think?” Shelby shook her head. “I turned and ran into the cat house. I figured he might not follow me inside. The cats get a little unhappy when people fight in front of them, and they were already all up in arms about something.”