The revelations came swiftly after that, but none of them staggered me as the first ones had. It was reported that he was a suspect in a cold-case murder from the mid-eighties. Of course he was. I expected nothing less of him. My girlfriend, who lived mostly in New York, slipped back there, away from Montana, during this interlude. My kids showed up every other weekend, but I was distant.

I called my mother to apologize. She’d been right about Clark, and her son had been an idiot. All she cared about was that his daughter had been recovered and the tortured dog had found release. “I’m curious if he killed those people,” she said.

“Of course he did,” I said.

“Did you ever have suspicions?”

Did I? As an English major at Princeton, I’d learned the phrase “suspension of disbelief,” but with Clark you contributed belief, wiring it from your personal account into the joint account that you held with him. He showed you a hollow tree; you added the bees. He gave you the phone number of the President; you added the voice that would greet you if you dialled it, and the faces of the Secret Service agents who would show up at your home a few days later. He gave you an envelope with a check inside; you filled in the amount.

Getting to know an old friend through his murder trial after failing to know him through normal means is a formula for humiliation. As Balian called his last few witnesses and reporters placed their bets, anticipating a hung jury, I started replaying scenes in my mind, imagining what would have happened had I been less eager to collaborate in Clark’s fantasies and cover stories. When fresh information discredits past perceptions, the underlying memories don’t change; you’re left to construct a new puzzle from the shaken-loose pieces of the old one. It’s infuriating. And the fury wants an object that’s not yourself.

All through the trial, Clark scribbled away on a pad, a goblinlike figure with pointy ears and a diffuse, pale bald spot that I kept staring at, needing a focus for my loathing. An anthropologist took the stand, and Balian projected on a screen photographs of the excavated yard and the sectioned, jumbled skeleton. The defendant peered up and squinted through his lenses, a strenuous stage squint meant to show the jurors that Clark was doing his level best to determine if these old bones were any he ought to recognize. I’d heard he’d been writing a novel. My source, who’d read parts of it, said that it was awful, a story set after the close of the First World War that sought to explain the roots of the Second World War. It looked as if Clark might have a lifetime to revise it.

The night after Balian made his closing argument (“Yes, I said he’s a master manipulator. I have never said he was a master murderer”), I rented a movie that I’d been meaning to watch and Clark might have seen in one of his classes. Its English title is “Purple Noon.” Its original, French title is “Plein Soleil_.”_ Made in 1960, the year before Christian Gerhartsreiter was born, it is the first film adaptation of Patricia Highsmith’s “The Talented Mr. Ripley.”

Alain Delon plays the social-climbing shape-shifter. He stabs rich Philippe Greenleaf (Dickie in the novel) while they’re out sailing in the Mediterranean, dumps his body in the sea, and then goes about impersonating him, concealing the crime by forging Greenleaf’s signature on some letters written on his typewriter that Ripley sends, postmarked Italy, to Greenleaf’s family. (Clark, according to the prosecution, had tried a similar trick with postcards supposedly signed by Linda Sohus, the victim’s vanished wife, which he somehow had forwarded from Paris.) Many other evasions follow, but just when Ripley thinks he’s in the clear the body turns up in a freak way, snagged on the sailboat’s anchor cable, and the game is up. This isn’t how Highsmith’s book ends. In the novel, Ripley gets away. He returns in a sequel, “Ripley Under Ground,” involved in a plot to counterfeit the work of a painter who committed suicide. I could have stayed up for hours spinning theories about Clark’s literary influences, but I didn’t have the heart. Even as a fraud, I decided, he was a fraud. He’d never had an idea of his own, not about how to speak or how to dress or which science-fiction TV show to obsess over or how to cover up a murder. He was wholly derivative.

The morning after I watched the Ripley movie, the jury reached its verdict. Clark squared his shoulders as his guilt was proclaimed. His attorneys looked distracted, but he seemed confident, genuinely confident.

I spoke with him in jail a few days later; it was the first time I’d seen him face to face in ages. The meeting started awkwardly. The heavy plastic phone receivers that allowed conversation through the glass didn’t switch on for a few minutes, forcing us to mouth inaudible greetings while gazing at each other from such close range that I could see light-colored, flecked irregularities in the iris of his left eye. The standoff became ridiculous. We smiled.

“You’re my first visitor,” he said when the phones went on. He asked after my children, a now creepy courtesy, and then, with two other prisoners crowding him from their adjacent conversation stations, he pushed his forehead up against the glass and asked for my help finding a literary agent. I lied, and said I’d look into it. What about the murder? Clark suggested that the wife did it. The Rothko and the Motherwell? Fakes. He gave me the name of a man who, he claimed, had pressed the paintings on him in the belief that their possession by a Rockefeller would provide them with “provenance” and allow them to be sold as genuine.

I scheduled another visit in a week; Clark seemed lonesome, and it was gratifying to have him finally at my mercy. In the meantime, I Googled the name of the art dealer he’d given me. Up popped several news stories in Spanish about a Canadian living in Peru who had kidnapped his young daughter the year before. Moving on in some branching way, I came across several longer stories, in English, about a scandal in the art world involving multimillion-dollar sales of counterfeit Motherwells and Rothkos. Another hollow tree; I had to stop myself. This time I didn’t want to see the bees.

On my second visit, I asked Clark why he’d run from California. “Oh, that,” I recall him saying; I wasn’t allowed to tape him in the jail. He insisted that his departure had nothing to do with murder. Instead, it had to do with a depressing meeting he’d had with Robert Wise, the director of such films as “West Side Story,” “The Sound of Music,” and “Born to Kill.” Clark sent Wise a stack of scripts he’d written. Wise returned them to him at a coffee shop, with blunt advice. “You have industry but no talent,” he said. Clark knew it was the truth and soon left town.

I gave up not long after that. I let fiction stand as fact, and I wasn’t surprised when I received a letter from Clark that seemed to confirm the central role of fiction in his life: “Few persons, especially not foreigners, have ever penetrated the Eastern Establishment to the degree I have, and all because of a novel my mother—an Americanophile—gave me at age ten so that I could learn English. What a story!” But I’d had enough of his stories by that time. I knew that, with Clark, I’d end up where I started, an object of manipulation. In Cornish, at the dinner he didn’t pay for, he’d asked me if I’d like to see a picture of his secret Canadian propulsion lab. He brought out a photograph from his jacket and laid it on the table, between our plates. It appeared to be taken from a plane and featured a dense, unbroken canopy of green deciduous treetops. I picked it up for a closer look.

“It’s right there,” Clark said. “Under all those leaves.” ♦