“I agree, Mrs. Hart,” Sherlock said, and took her arm and led her in the glass-walled living room, with Mrs. Hart craning her head about to look at her husband. It was silent in the room except for Mrs. Hart’s heavy breathing and the crackling of a fire that burned brightly in the fireplace.

Sherlock released Mrs. Hart’s arm. “So you have information your husband killed Tommy Cronin? You know Tommy was blackmailing him because he and Peter had that video on the disk?”

She stared at Sherlock. “I heard him screaming one night that Stony had fixed the damned surveillance system, and he was banging his fists against the wall in his study he was so furious. I asked him why that was a problem, but he wouldn’t tell me. Then he ran into the control room behind and tore out the system, tore it out with his bare hands, and he never stopped cursing. He frightened the girls.”

Savich said, “You had no idea, did you, Mr. Hart? Stony liked to fix things, decided to fix the surveillance system and didn’t tell anyone. Maybe he thought it was funny to spy on his family with his friends when they were bored. I’d have to say he was surprised when he saw his father committing a major felony. Tommy, Peter, Stony, all of them must have been having a fine time until they saw you on this video.

“They all knew banking and finance, knew exactly what you’d done. Stony probably made Tommy and Peter swear they’d never say anything, but Peter was Peter, wasn’t he, Mr. Hart? A greedy manipulator. I don’t doubt it was Tommy who called you, demanding money. Peter would have put him up to it.”

“This is all nonsense, all of it.”

“Shut up, Wake! That is exactly what happened, isn’t it?” She looked like she would have run at him, but Sherlock again held her in place.

Savich continued, “Tommy was flush with cash in December, as was Peter. They got that cash from you, after Tommy sent you a copy of the disk. I’ll bet he promised he’d give you the original and you’d never hear from him again.

“But Peter wouldn’t let this gold mine go, and you did hear from Tommy again, so you met him at your office on M Street, which just so happens to be on the third floor of the Hampton Building, and you threw him out your window.”

Hart listened, saying nothing, fists at his sides, shaking his head back and forth.

“Quite an idea to leave his body at the Lincoln Memorial, to send us off in the wrong direction, at least for a while. But you overthought what you did next. You thought you understood your son Stony’s anonymizer software, you thought no one on earth could ever trace anything sent using it, but the thing is, Mr. Hart, you didn’t understand as well as your son did, and we traced the photo you uploaded of Tommy Cronin’s body back to Stony’s computer.

“And that brought Tommy Cronin’s murder right back to you.”

Carolyn Hart was panting now, nearly hysterical with rage. “Even I didn’t think you uploaded that horrible picture from Stony’s computer yourself! Stony wasn’t even involved. Stony knew you’d done it, knew you’d killed his friend, and he couldn’t bear it and he killed himself!”

Hart kept himself in tight control. “Shut up, Carolyn. You have no idea what you’re talking about. They have no proof of anything at all.”

Savich shook his head at him. “No proof, Mr. Hart? We found a lot of cash in Peter’s apartment. Your cash, Mr. Hart, because he didn’t withdraw it from his own bank account. He didn’t have that kind of money. Neither did Tommy. But you made a large withdrawal from your brokerage account in early December, deposited in your bank account. Then you made three large cash withdrawals, two in December, and one yesterday, Monday. What happened, Mr. Hart? Peter called you, didn’t he? He told you he had copies of the disk, too. Knowing Peter, he would have tried to persuade you it wouldn’t do to try to kill him, as you killed Tommy, that he had copies hidden away.”

Hart walked to the middle of his modern living room surrounded by falling snow and pulled out his speaker’s voice, smooth and deep. “I want you out of my house. I’m going to call my lawyer.”

“Feel free,” Sherlock said. “But before he arrives, you might as well know our lab will be looking for trace evidence in all of your cars. If you used any of them to haul Tommy’s body to the Lincoln Memorial, they’ll find it. We’re going to track your whereabouts, and Tommy’s, on Friday night, and we’ll be searching your office and the concrete sidewalk under your office windows. A human body that falls onto concrete from that height leaves traces. Your phone records, and Tommy’s and Peter’s—there will be calls you have no good explanation for. You cannot hope to get away with killing them, Mr. Hart.”