The Rev. James MacDonald founded Harvest Bible Chapel in a Chicago suburb in the late 1980s, and over the years his profile grew in tandem with the church’s. Harvest expanded to multiple campuses that drew 12,000 people to weekly services and became one of the 50 largest churches in America. MacDonald was a nationally sought-after speaker, a radio and television preacher, and the author of books including Act Like Men: 40 Days to Biblical Manhood and Lord, Change My Attitude. Meanwhile, its critics say, the church amassed millions in debt while the motorcycle-riding MacDonald lived large and treated his perceived enemies ruthlessly. The final blow to MacDonald’s leadership came in February from an unlikely source: a local radio shock jock.

Questions about MacDonald’s leadership had been swirling for years. Problems were first raised in 2012 by two former church members who documented the church’s complicated finances on their blog, and accused it of accruing $44 million in debts. Other disgruntled ex-leaders and members later began speaking publicly about their experiences. Then a freelance journalist named Julie Roys began investigating the story in earnest last year. MacDonald and the church responded by suing the two bloggers, their wives, and Roys for defamation last fall. The church dropped the suit in January after a court ruled that documents in the case could be made public.

Roys’ devastating piece of investigative reporting was published in December by the conservative evangelical magazine World, and included details about the church’s finances along with accounts from former employees and church members who said MacDonald “fostered an abusive and fear-based culture.”

All of that was before Mancow Muller, who has been a fixture in Chicago since the 1990s, started speaking out. Muller has a reputation as “the wild man of Chicago radio,” known for stunts like taping himself being waterboarded and for racking up big fines from the Federal Communications Commission. Muller had also attended MacDonald’s church since 2014. The two local celebrities became close, and Muller admired the older pastor. They traveled together and spent time together outside of church. On a trip to Israel last year, Muller says that MacDonald baptized him in the Jordan River. “I was one of his dummies,” Muller told me in a private message on Twitter. “We wanted to believe that that guy up on stage was real and genuine and actually cared about us and our families and was channeling Jesus Christ.”

Muller said he grew suspicious of MacDonald when, he claims, the pastor asked him to donate $3 million to the church. “[He] told me that he would be blessed more because he gave more than me,” said Muller, who was out of work at the time. Muller also recalled that MacDonald suggested he buy a house in Florida for Muller’s retirement and then leave that house to the church. Muller said he’d grown suspicious, too, of MacDonald’s handling of the lawsuit against his critics last year, and of the way the pastor discouraged his followers from reading anything negative about the church. He broke with MacDonald publicly last month in a scathing op-ed in a local newspaper, in which he accused MacDonald of fostering “a culture of authoritarianism, secrecy, intimidation, outlandish fundraising expectations, poor financial controls and debt.” Muller described the atmosphere at Harvest as “cult-like,” and he urged parishioners to stop donating money to the church.

In February, Muller escalated his crusade by airing clips on his show that seemed to capture MacDonald privately insulting his perceived enemies in terms that would be shocking to his followers—though not, perhaps, to Muller’s own listeners. The voice in the clips refers to the idea of planting child pornography on the computer of Christianity Today CEO Harold Smith in retaliation for the magazine’s coverage of him. It calls the magazine’s editor in chief, Mark Galli, a “certifiable prick,” and jokes that Galli and Julie Roys had an affair. (Roys firmly denies this on her blog and calls the joke “disgusting.”) It calls the magazine an “Anglican, pseudo-dignity, high church, symphony-adoring, pipe organ-protecting, musty, mild smell of urine, blue-haired Methodist-loving, mainline-dying, women preacher-championing, emerging church-adoring, almost good with all gays and closet Palestine-promoting Christianity.” Parsing those epithets would make a decent master’s thesis on contemporary American evangelicalism.

The next day, the church’s leadership board fired MacDonald “for engaging in conduct that the Elders believe is contrary and harmful to the best interests of the church.” In a statement posted to the church’s website, the all-male elder board wrote that they had been considering MacDonald’s removal for some time, but the “highly inappropriate” tapes on Muller’s show accelerated the decision. Muller hasn’t backed down since MacDonald’s firing. On his Feb. 18 radio show, he interviewed a former Harvest music leader named Anne Green who said MacDonald once touched her leg near her crotch on a private plane in or around 2005. (The church issued a statement saying it had investigated the allegation last fall and failed to corroborate it.)

“I was one of his dummies,” Muller said in a Twitter DM . “We wanted to believe that that guy up on stage was real and genuine.”

A few days later, Muller invited Roys on his podcast, where he played more excerpts from the tapes, and revealed that one of the voices MacDonald was speaking with belonged to public relations executive Johnnie Moore, one of President Trump’s evangelical advisers. At one point, Moore seems to agree when MacDonald calls Galli, the Christianity Today editor, a “certifiable prick.” In a statement, Moore said his job sometimes involves acting as a “shock absorber” who listens when clients become frustrated. But “the fact that it was a private conversation, meant to absorb the emotions of the moment, did not make it right for me to respond offensively and thoughtlessly. I’m very sorry for that, and I’m dealing with it directly, seriously and personally.” (Requests for comment emailed to MacDonald, his office at Harvest, and his long-time assistant did not receive replies.)

MacDonald is the second Chicago-based megachurch pastor to fall dramatically from power within the last year. Last April, Willow Creek founder the Rev. Bill Hybels resigned after multiple women accused him of misconduct. That church has seen significant declines in attendance. MacDonald’s downfall also echoes that of formerly Seattle-based pastor the Rev. Mark Driscoll, with whom he was once close. Driscoll resigned in 2014 over criticisms of his authoritarian leadership style and use of crude language. He moved to Arizona and started a new church there.

For now, the church MacDonald built is in chaos. His two sons resigned from their jobs at the church last week. Church members are calling for the resignation of another senior pastor, plus all of the church’s elders. Headlines about MacDonald’s disgrace dominate Christian media outlets. Muller tweeted that his former friendship with MacDonald could make a great movie someday: “The so-called ‘shock jock’ that found out that this mega church spiritual leader was a demonic fraud.”