The comment about the security tape reminded Rhyme of something. “And the videos Stefan made? You had him do that?”

“No, no. His own idea, actually. We thought he might leave a noose and maybe a note to the press. But he thought the video would make the world think he was truly psychotic.”

“Why the waltz?” Spiro asked.

“He loves them, for some reason. He’s never told me why. Something about his parents, I think. This might be too tidy, but they weren’t married when he was born. He was ten when they got married. I saw a picture of them dancing together. Stefan was there, watching them. She had problems too, drinking and prescription drugs—and serial affairs. She eventually killed herself. His father just vanished. disappeared. Maybe he associates waltzes with a happier time. Or a sad time. I don’t know. He told me he found his mother’s body in the family cellar.”

“She hanged herself?”

“That’s right.” McKenzie shook her head. “What a terrible thing for a child to see.”

Explains a few things, Rhyme reflected. In this line of work you reject the obvious, and dig for unnecessary subtlety, at your peril.

“He wouldn’t say anything more. No reason for him to. We’re close in some ways. Close enough so that he does whatever I ask him to. Well, whatever Euterpe tells him.”

Sachs said, “You’re Euterpe. His muse.”

“That’s what he calls me. When I said I could get him access to music and computers, he hugged me and said I was his muse. I’m his inspiration to get to Heaven—well, he calls it Harmony. Stefan has a very complex worldview. It’s based on the medieval concept of the music of the spheres. And I’m helping him on his way to enlightenment—Harmony.” McKenzie’s face broke into a smile. “And you, Detective, are Artemis. The goddess of the hunt. We’re half sisters, by the way.”

Ah, that was Stefan’s meaning not long ago.

Rhyme said, “Okay. The big question: How successful was AIS here?”

“Very. We found out through our techniques that Ali Maziq’s terrorist assignment was to travel to Vienna, collect explosives from a garage outside of town and detonate them in a shopping mall.”

Rhyme recalled that Henry Musgrave, the consulate general, had told them about a foiled attack.

“The calls to Bolzano,” Spiro said. “The Trenitalia trip, six hours to get him there.”

“Yes. He’d meet a German-speaking contact who would drive him into Austria. We didn’t have a chance to interrogate Malek Dadi before he was killed. His target was in Milan. But you helped us there—finding the Post-it note with the address of the warehouse in Milan.”

Sachs shook her head. “Ah. Your quote ‘legal liaison,’ Prescott? He’s with AIS too. Of course. Before Mike Hill’s private plane landed at Linate, I gave Prescott the address of the warehouse. But he didn’t drive me right there. He took me all over Milan, complaining about the traffic—but that was to give your team time to raid the place. I found a broken beer bottle on the driveway apron. Your people must’ve finished removing the explosives just before we got there.”