Potter nodded gratefully. “Yes, it was! I thought I could stab him while he slept and he’d never even know what happened. But the knife wouldn’t go in! And then he woke up and started to struggle. It was horrible!”

“I’m sure it was pretty horrible for Mr. Dudley, too,” Frank reminded him.

Potter had the grace to flush. He lowered his gaze.

“All right, so I know why you tried to kill Dudley. It’s no mystery why you killed Calvin, either. How did you get him to drink the arsenic?”

Potter raised his eyes. “I deeply regretted having to kill the boy. I know he never did any harm, but-”

“Potter, don’t make me hit you,” Frank warned. “And if you keep pretending you’re sorry you killed that innocent boy, I might have to break your jaw. And a few ribs if I don’t think you’re repentant enough.”

Potter swallowed nervously. “What do you want to know?”

“Just tell me how you did it,” Frank said through gritted teeth. “And try not to say anything stupid enough to make me forget I want you in one piece until you’ve finished your confession.”

“I brought him the sarsaparilla,” he said quickly. “I told him it was a treat, to make up for how badly things had been going for him. He was very pleased.”

“I’m sure he was.” Frank restrained himself with difficulty.

“After he started getting sick, I helped him get to bed and offered to fetch a doctor. Then all I had to do was wait until he passed out. I’d already written the note, so I put it and the arsenic on the bureau. When everyone else in the house had gone to bed, I left.”

Frank managed to hold his fury in a tight, white ball inside of him. He’d let it go in a minute, just as soon as he had the last of Potter’s confession. “Now tell me why you killed Blackwell.”

Now Potter looked really frightened. He swallowed again. “Could I have some water?”

“No, just start talking.”

“Well, you know what Edmund had done. He’d involved Letitia in a bigamous marriage, and the scandal was going to break unless someone stopped Calvin Brown.”

“I thought Blackwell was going to pay him off and send him away.”

“Edmund thought that would be enough, but I knew that a blackmailer is never satisfied. The Browns would have wanted more and more from Edmund. You can’t keep a secret like that for long, either. Edmund had enemies, doctors whose patients he’d been able to cure where they had failed. They would have been only too happy to expose him as a bigamist. They wouldn’t care if they destroyed Letitia’s life in the process.”

“So you decided Blackwell had to die?” Frank asked incredulously.

“Don’t you see? It was the only way! If he was dead, the Browns couldn’t blackmail him. Letitia would be a respectable widow and…”

“And what?” Frank insisted.

Potter lifted his chin defiantly. “She would have had people who truly love her to look after her best interests.”

“Like you?” Frank suggested.

“I will always be Letitia’s devoted servant.”

Frank managed not to choke. “I guess you knew Blackwell would be alone in the house that afternoon,” he suggested.

“I knew he was going to meet with the boy. He’d asked me to help him get the money together, you see.”

“That’s right, you already told me that part. Did he also ask you to be with him when he met with Calvin?”

“No, I went there on my own, knowing he’d be alone. I tried to convince him once more not to allow himself to be blackmailed, but he wouldn’t listen to me. We quarreled bitterly, but I still couldn’t persuade him. I could see reasoning with him was hopeless, so I reached into the drawer where I knew he kept his pistol.”

“How did you know that?”

“He’d shown it to me on several occasions. Having a gun for protection is only effective if people know you have it, Mr. Malloy.”

“Did Blackwell think he needed protection from you?” Frank asked with interest.

“I don’t believe he did,” Potter replied stiffly.

“So you pulled out the gun. Wasn’t Blackwell sitting right there at the desk? Didn’t he try to stop you?”

“I don’t suppose he thought I was any danger to him. In any case, he didn’t do anything to stop me. He just sat there and… and stared at me. I knew what I had to do, so I pointed the gun at his head and fired.” He looked at Frank expectantly, although Frank didn’t know what he was expecting.

“Then what happened?” Frank asked.

“He… he slumped over the desk, just like you found him. And I left the house. No one saw me.”

“What did you do with the gun?”

“The gun?”

“Yes, did you take it with you?”

“I… no, of course not, I… I must have dropped it. I really don’t remember.”

“Did you touch anything on the desk or in the room?” Frank prodded.

“I… I don’t remember. It was so horrible. I think I just ran out.”

“Didn’t you take the money Blackwell had gotten to give Calvin?”

“Certainly not! I’m not a thief,” Potter insisted, offended. Apparently, he felt he could commit murder but still maintain some integrity by not stealing from the dead man.

“Then what happened to the money?”

Potter looked genuinely baffled. “I have no idea. Probably one of your policemen took it. Or one of the servants. How should I know?”

Frank sighed. “All right, so you ran out. Where did you go?”

“Back to my flat. I… I waited awhile. Then I was going to go back to discover the body. I didn’t want… Well, I certainly didn’t want Letitia to find it.”

“Of course not,” Frank said. He’d proven he’d do almost anything to protect Letitia Blackwell from unpleasantness. Unfortunately, he’d also just proven he hadn’t killed Edmund Blackwell.

SARAH HAD MANAGED a few catnaps during the night but nothing approaching real rest. Since the room was warm, she’d appropriated Dudley’s blanket and made herself a crude pallet on the floor. She could have slept even in such uncomfortable conditions, but Dudley kept waking up from pain or thirst all night. She’d changed his bandages once when he’d opened one of his sutures, and just when she’d finally dozed off the last time, the landlady had come pounding on the door, demanding to know if Sarah wanted some breakfast brought up.

The next time Malloy needed a nurse, he could just hire one.

Dudley woke up moaning as the landlady delivered the breakfast tray.

“He ain’t going to die, is he?” she asked Sarah. “I don’t need nobody dying here. It’s bad for business.”

“I’ll do my best to see that he doesn’st,” Sarah assured her. “I wouldn’t want to inconvenience you in any way.”

The sarcasm was wasted on the landlady, who just nodded her approval and left.

Sarah checked Dudley for fever. He seemed warm, but not too bad. No signs of serious infection yet, but it was still early. “You need to eat something,” she told him when she’d examined his bandages. “Do you think you could manage it if I help you?”

“I don’t… I’ll try,” he said. “It hurts, though.”

“I don’t want to give you any more medicine until you’ve tried to eat,” she explained. “The medicine always makes you fall asleep too quickly.”

He nodded and closed his eyes against the pain while she pulled the chair closer so she could feed him. Sarah had asked for soft foods, and that’s what she’d gotten. Milk toast and something that might have been porridge.

He managed to swallow a few bites, and then he said, “Was I dreaming, or did you tell me that it was Mr. Potter who tried to kill me?”

“You weren’t dreaming. He’d lost his watch fob in the struggle with you, and I found it last night, under your bed. Mr. Potter realized he’d lost it and came back looking for it. Since he thought you were dead-that’s what Mr. Malloy told him-he thought it would be safe. Instead, he got caught.”

She didn’t see any point in telling him how she’d fought and overpowered Potter. She wasn’t interested in impressing him, in any case.