And throughout this rise of interest, there was a parallel rise in debunkers. The poet Robert Browning once exposed the mid-19th century Scottish psychic, Daniel Home, who claimed to conjure the spirit of Browning’s infant son, who died young. Except Browning hadn’t lost a son. Worse, the poet lunged at the apparition to unmask it and found himself clutching Home’s bare foot. Helen Duncan was found to swallow a length of cheesecloth, which she could produce dramatically from her mouth as ectoplasm. During an early-20th century séance, Frederick Munnings deployed a long voice-altering trumpet across the room — a clever tactic undermined one night when someone accidentally switched on the light.

The idea of talking with the dead is one of those stubborn hopes that’s difficult for a culture to move beyond. Famous skeptics like Harry Houdini left precise instructions with his wife and friends as to just how he would reach out, if it were possible, after his death. Stanley Kubrick, in talking about his movie “The Shining” with Stephen King, confessed that he found optimism in stories about the supernatural. “If there are ghosts, that means we survived death,” he explained.

Gerbic got into the sting racket because of her mentor, James Randi, the famous skeptic who started his career as a magician, the Amazing Randi. After he began busting paranormal con artists as a hobby, Randi won a MacArthur grant that he leveraged into a variety of different venues, including annual ship cruises filled with skeptics, called the Amazing Adventure. On a 2009 voyage to Mexico, Gerbic met Edward, who was on board as the skeptics’ entertainment.

Edward himself is a mentalist and claims no powers other than to entertain. He once posed as an undercover clairvoyant to infiltrate the Psychic Friends Network, which became popular as late-night infomercials that offered psychic readings over the phone in the 1990s. For another Psychic Friends spinoff radio program, he climbed the heights of the organization and became the backup to the show’s Master Psychic. Edward wrote a book about his clandestine life as a medium, “Psychic Blues.”

After they became friends, Gerbic and Edward found themselves griping to each other that skeptics had become too much of a closed group, too often just patting each other on the back. Skeptics’ groups, Gerbic told me, “always seemed to be bogged down by bureaucracy and rules,” and she really wanted “to do something and stop talking about it.”

Then Edward happened upon a new way to lure people into the realm of reason. Instead of just busting psychics outright, he focused on helping the audience members discover the ruse. Edward was at a 2009 show featuring a giant of the business, Sylvia Browne, who was performing at the Gibson Amphitheater in Los Angeles, hosted by the TV celebrity Montel Williams. At the time, Browne was making a comeback from a few psychic catastrophes. Browne told Lynda McClelland’s daughters that their mother, who had disappeared, was alive and in Florida. Later, McClelland’s body was found near where she lived in Pennsylvania. Browne also predicted that an 11-year-old named Shawn Hornbeck in Missouri had been kidnapped by a brown-skinned man in dreadlocks and was dead. Then Hornbeck was found alive — kidnapped by a white guy with tedious hair.

During the Q. and A. session, Edward managed to get to the microphone. He told Browne he was possessed by spirits, fell into a trance and started to name them: “Lynda McClelland!” On YouTube, you can see Browne barrel onward, even as Edward pretends to collapse, and move to the next audience member with startling speed.

One day, at a skeptics’ meeting in 2011, Gerbic and some others realized that Sylvia Browne was just down the street. They decided to sabotage her show but with a slight twist. They couldn’t guarantee getting someone to a microphone; instead, they just handed out cards to people entering the show. The cards said nothing more than “Shawn Hornbeck” and “Lynda McClelland” — the idea being that for some audience members, a little curiosity and Google would handle the rest.

Gerbic told me that the group’s previous hot-read sting — Operation Pizza Roll — worked perfectly back in 2017. She and the other skeptics spent 10 days creating Facebook profiles in advance of Thomas John’s visit to southern Los Angeles. Gerbic used her Facebook sock puppets, “Susanna and Mark Wilson,” to register herself and her pal Edward.

John is a well-known figure on the psychic circuit. He names people’s pets and dead relatives with breathtaking first-attempt accuracy. He has a thriving practice on Madison Avenue, and on the West Coast, his press materials tout a host of Hollywood clients, including Sam Smith, Courteney Cox and Julianne Moore. His audiences admire him, but then they probably haven’t Googled past the first page of results to learn that before he popularized his gift for talking to the dead, he was Lady Vera Parker, a drag queen in Chicago who later got into some trouble when Thomas John Flanagan (his legal name) was charged with theft, fined and sentenced to probation — precisely what the specific charge was for, his lawyer explained in a statement, the psychic can no longer remember.

On the appointed night of the show, in came Susanna and Mark Wilson, dressed in fancy clothes and toting third-row V.I.P. tickets and unobtrusive recording equipment. Because Susanna’s Facebook page mentioned her losing her twin brother, Andrew, to pancreatic cancer, Gerbic arrived clutching a handful of tissues, a tactic she encourages because it sends the psychic the message that you will be an emotional and entertaining reading. Right away, Thomas John said he was tuning in to a twin brother who wanted to speak to his sister. Gerbic raised her hand.

“Somebody is making me aware of cancer?” John asked, and Gerbic choked up, yes, yes. John reeled her in: “I’m getting something right in here,” and pointed to his abdomen, “stomach or pancreas?” Gerbic acted emotional. And John went straight down the rabbit hole, all the while being careful not to bring the crowd down. He said of Gerbic’s fictional dead brother: “First off, he is making fun of you, teasing you for being here with me! He’s laughing about it!” And the audience laughed, too.

Over the course of the reading, John comfortably laid down the specifics of Susanna Wilson’s life — he named “Andy” and amazingly knew him to be her twin. He knew that she and her brother grew up in Michigan and that his girlfriend was Maria. He knew about Susanna’s father-in-law and how he died.

But about two-thirds of the way through John’s riffing, he seemed to sense something was fishy. All of which is, in fact, part of the experiment. Gerbic knows only some of the facts of her character’s life. Her thinking is that if John knows even more details than she does, then it’s absolute proof that he’s looked through the Facebook posts. Gerbic’s sting is placebo-controlled, double-blind. On the tape, it’s easy to catch the precise moment when John sensed that something was wrong. John was talking about the dead brother when he suddenly asked, “And ‘Buddy,’ who is that?”

Gerbic had no idea and improvised, “my father,” when in fact, Buddy was her fictional dead brother’s fictional dog.

John kept up the reading and then interrupted himself: “Oh, I understand — O.K., so I am being drawn over here,” and with that, he walked away.

Back home, Gerbic and Edward excitedly checked to make sure her hidden tape recorder captured the whole moment. Later, Gerbic explained: “One really odd thing happened to me a couple days after the event. I received a tweet from Thomas John to my Susan Gerbic account with only a heart.” How else could that have happened, Gerbic asked, other than that John was winking at her — going back to Susanna Wilson’s ticket purchase to discover it was paid for by Susan Gerbic.

When I reached Thomas John, he insisted he did not use Facebook. He explained away the incident without hesitation. “I do remember her coming to an event,” he said. “I recognized her because she was there with that other guy who wrote that book.” He went on to say that if there is tape of his giving them a reading, well: “I have my eyes closed for an hour and a half when I’m doing readings. If she spoke up during that period of time, I don’t remember that. It’s possible.” John said he didn’t remember sending Gerbic a tweet after the show, but added: “I tweet a lot of people. I don’t remember doing that, but it’s possible.”

Then John pivoted, arguing that the entire experiment wasn’t really scientific enough. “For Susan to come to a reading and get a two-minute reading and say, well, ‘I made a fake post about my dog, Buddy, and my father who died,’ it’s really not any sort of scientific testing of psychic powers.” He added, “First off, someone will have to be a scientist to do a scientific experiment, not someone who used to be a photographer at Sears.”

Since the sting, Thomas John used his prestige out West to launch “Seatbelt Psychic,” a show on Lifetime in which he “surprises unsuspecting ride-share passengers” when he “reveals he can communicate with the dead.” James Corden, the host of “The Late Late Show,” gushed that he is “obsessed with the show,” which resembles Jerry Seinfeld’s Netflix series “Comedians in Cars Getting Coffee,” except instead of comedians drinking coffee, it’s folks talking to the dead.