Shortly before six that Saturday evening, I was on my second cup of coffee at the Mandarin Oriental bar when the man I was waiting for entered, looking harried and jittery, a backpack slung over his shoulder.

I left my coffee cup to cut across the lobby to intercept him.

“Dr. Winters?” I said.

The concierge doctor started and seemed puzzled and then threatened by my presence.

“Dr. Cross? What are you doing here?”

“Can I have a few moments of your time?”

“I have a patient waiting.”

“The patient’s me.”

He looked confused. “What’s wrong?”

“Just a few questions we need answered sooner rather than later.”

Winters, who was in his early forties, scratched at his hand. “I get paid for this, you know, making calls.”

“The FBI will cover your fee. Can I get you something to drink?”

“Bourbon,” Winters said.

A few minutes later, a waitress set a tumbler with two fingers of Maker’s Mark in front of Winters; he raised it, drank it down, and ordered another.

“What do you need?” he said.

“What was your relationship to Viktor Kasimov?”

“I was his doctor.”

“Nothing else?”

“No. What do you mean?”

“I’ve read the file on your medical-license review,” I said.

Winters got disgusted and then angry. “I’m clean, and I have been clean for almost four years.”

“You were reprimanded for overprescribing pain medication,” I said.

“Four years ago,” he said.

“So you didn’t give Kasimov a script for Oxy?”

“No. He had a stomach bug. Why would I?”

“What about seeing makeup and masks? You neglected to tell us about that when we spoke.”

Winters ducked his chin, and you could tell he was wondering how the hell I knew that, and then he did know.

“That psycho bitch tell you that?” he asked. “Kaycee?”

I was almost going to correct him, tell him her real name, but instead I nodded. “She did. She thought it was the right thing to do.”

“I’m sure she did,” the concierge doctor said, almost sneering. “But so what? Is it a crime?”

“Depends,” I said. “If Kasimov’s men donned disguises to go to a liquor store, no. But if they went out and were involved in a conspiracy to assassinate the president, it’s quite a different story. A case could be made for your aiding and abetting murder.”

Winters’s hands flew up in surrender. “No way. They told me they just needed to be able to visit the Russian embassy without attracting attention. I swear to God.”

I studied him, thinking that I didn’t trust him. “Kasimov or his men mention where they were going the last time you saw them?”

“London,” the doctor said. “I told him to see a doctor there if he was feeling dehydrated after his sickness and the flight. That’s it. End of story.”

“Okay,” I said. “If you think of anything else, here’s my card.”

He took it without enthusiasm, didn’t look at it, and stuffed it in his pocket.

The waitress came with his second drink. I threw down two twenties and got up.

“My address is on the card,” I said. “Send your bill there.”

“No. No charge.”

I started to walk away.

“Dr. Cross?”

When I looked back, I saw he had my card out and was playing with it in his fingers. “Yes?”

“I…” He paused to look at his bourbon. “Do you think people like me, addictive personalities—do you think we can ever stop our obsessions?”

“If you’re sufficiently motivated to change, yes,” I said.

“So someone else can’t stop you?”

“When it comes right down to it, change has to come from within.”

Winters nodded and pushed the bourbon away from him. He gazed at me and said, “Thanks.”

“Anytime.”

As I turned to go again, he said, “I tried to change Kaycee, or whatever her name really is.”

I paused, unsure of what to say. “Didn’t work?”

He shook his head. “She’s crazy. Crazier than I ever was.”