My employer pursed his lips and looked as one might while deciding whether or not to reveal the truth about the tooth fairy to a child who has failed to receive a coin beneath her pillow. He spoke in a measured tone. “Miss Rook, I’ve not decided on Mr. Cane’s guilt by any means. He did say that his life is complicated, and I believe he was telling the truth about that. Do consider, however, the circumstances by which you found him innocent. During his visit to the cell, it became clear he could hear the banshee’s wail—which suggested that he, too, was going to be a victim. As it turns out, though, everyone heard the wail, so we must assume that the murderer heard it, as well. The incident proved nothing.”

I let the idea sink in. The shadows to every side darkened, and terrible fangs and bloodshot eyes inserted themselves behind every tree trunk. Something rustled in the foliage beside us, and—I’m not proud to admit it—I squeaked and leapt backward. A pigeon burst from the leaves and settled itself into the eaves of a building half a block down the lane.

“Then again, it may have proven slightly more than nothing,” Jackaby amended, oblivious to my outburst. I hoped that he would be more aware of my distress if I were ever ambushed by a real nefarious fiend, but for the sake of my dignity I chose not to mention it. He went on, burrowing into his thoughts. “It reveals that the murderer was aware of Mrs. Morrigan—aware of who and what she was. With the banshee still living, each victim was alerted before the kill. So long as Mrs. Morrigan remained alive and keening, we had at least a clue as to where our killer was going next. He slaughtered her to eliminate our advantage.”

We crossed the street, and I recognized where Jackaby was leading us. Half a block ahead stood the Emerald Arch. “Think we’ll find any new clues?” I asked.

Jackaby shrugged. “Possibly. But I’m not here for that.”

“Then, why . . . ?”

“This time, I am here to pay my respects.”

Marlowe was at the front door, giving instructions to a few of the uniforms when we arrived. He spotted our approach and held up a finger for us to wait while he wrapped up with the officers. Once he had sent them on their way, he turned and fixed us with a stare for several long seconds.

“I told that boy to go get some rest, and we’d release you two in the morning. I swear, before you got involved, Cane was one of my best detectives. Reliable. Loyal to a fault. He would never ignore a direct order. You’re a bad influence.”

“I do what I can.”