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We Now Know Who Was Behind The Irrational Bombing Case — All the Shocking Answers from the Finale

Alec Mercer's ex-wife has made a major break in the case — one that leads to tragic consequences.

By Jill Sederstrom

The mastermind behind The Irrational’s deadly church bombing has been revealed — and the clever killer was hiding in their midst the entire time.

How to Watch

Watch The Irrational Mondays at 10/9c on NBC and next day on Peacock

In a dramatic Season 1 finale, Alec Mercer (Jesse L. Martin) and his FBI agent ex-wife, Marisa (Maahra Hill), discovered the mastermind behind the bombing— and Jace’s killer—was none other than Marisa’s boss at the FBI, Bob Caswith (Garry Chalk).

It turns out Bob, who used the name Mathias for his illegal deeds, was acting in misguided allegiance to the powerful Senator Kevin Sanford (James Tupper) and orchestrated the 2002 explosion to cover up the death of a campaign aide.

So just how did the whole plot play out? Here’s everything to know about the bombing and the men behind the deadly act:

What happened in the church bombing on The Irrational?

It all began nearly 20 years ago, when Alec survived a church explosion that killed 13 people and left him with burn scars, clouded memories, and guilt, as he couldn’t place the bomber at the scene. 

That meant the only assailant identified in the plot, Wes Banning, was convicted on lesser charges.

For decades, authorities believed Wes acted as a “lone wolf” in the bombing, until Wes seemingly tanked his own parole hearing after seeing a shadowy figure appear at the door of the hearing, leading Alec and Marisa to suspect he didn’t act alone.

Who are the suspects involved in The Irrational’s church bombing?

The FBI agreed to reopen the case, with Marisa and Jace at the helm of the new investigation. 

RELATED: Everything We Know About The Irrational Season 2

After 19 years, Banning agreed to an interview with Alec’s FBI agent ex-wife, Marisa, and agreed to make a “full confession” in Episode 4.

“It was me. I bombed the Methodist Church in April 2002. There was a big boom and then fire. I like fire, 13 dead. Will that suffice?” he said.

Wes Banning appears outside a house in The Irrational Episode 110.

But when Marisa confronted him about her theory that he didn’t act alone, Wes suddenly clammed up.

The investigators got a new break in the case after Alec recovered a memory from the bombing and recalled seeing a getaway van with a distinct dry cleaning logo. Marisa was able to link the van to a fundamentalist group called the New Apostles.

After eliminating members of the group who were either dead or incarcerated at the time of the bombing, they identified a suspect named Peter Shelby. But by the time they arrived at Peter’s home, he was already dead in what they concluded was a murder staged to look like a suicide.

They came to believe that while Wes, who had a history of attacking empty government facilities, built the bomb, Peter had been the one to plant it at the church. 

Peter’s mother seemingly confirmed their hunch when she admitted that he did set off the bomb as part of a desire to “return this country to its roots,” but said he didn’t mean to hurt anyone and accidentally set the timer for 60 seconds instead of 60 minutes.

“He said no one was supposed to die,” she said. “He only wanted to get the church. It was six months after 9/11 and those Methodists were loaning their church to a mosque.” 

She told authorities that a third man known only as “Mathias” had been behind the whole plan.

“Peter was in way over his head,” she said.

Who is Mathias on The Irrational

Investigators were now convinced that the key to cracking the mystery was identifying Mathias, but they had few clues to go on. They kne he is white, “fancy,” and wears a “flashy gold watch,” but that’s about it.

In Season 1 Episode 9, Marisa and Jace considered the possibility that “Mathias” was really Senator Sanford (James Tupper). The political candidate had delivered a speech at  the church just before the bomb went off. Sanford had been behind in the polls at the time and they thought maybe he’d arranged the bombing himself to get a sympathy vote at the polls.

Jace Richards and Marisa sitting next to each other in a dimly lit room.

Marisa went to vet out the theory by pretending to consider a political race of her own and seeking Sanford out for his advice. Sanford admitted during their discussion that while he did get some “sympathy votes” after the bombing, he had actually already pulled ahead in the internal polling numbers and didn’t need the bump. 

Who was the target of the church bombing on The Irrational?

Yet, Marisa still wasn’t convinced the bombing wasn’t tied to Sanford in some capacity and began to suspect that maybe the real target of the bombing had been someone specific, who was scheduled to be on Sanford’s cleanup crew that night. 

As she and Jace got closer to revealing the truth, viewers learned at the end of Episode 9 that someone has bugged her downstairs closet and was listening in as the investigators try to piece the case together.

Alec and the FBI got one step closer to unmasking Mathias in Episode 10 after a prison van crash gave Wes the perfect opportunity to escape. A desperate Wes, who believed Mathias was trying to kill him behind bars, armed himself with a vest bomb, then went to Alec’s office, where he took the behavioral science professor and his two research assistants, Phoebe and Rizwan, hostage.

It’s then that Alec learned that Mathias has been threatening to hurt Wes’ daughter, Dahlia, for years, if he didn’t agree to do whatever Mathias asked.

Wes admitted to giving Mathias the bomb used in the explosion.

“I didn’t know there was a church. I didn’t ask what it was for,” he said.”I just gave Mathias what he wanted and I hoped that would be the end of it.” 

But the day before Marisa arrested Wes, Mathias tracked him down and showed him a photo of his daughter Dahlia living a happy life with her foster family. 

“He tells me that Dahlia is with a loving family and that’s she’s going to have a wonderful life if I do as I’m told and if I don’t, well, her life will be short,” Wes said.

Alec Mercer on The Irrational Episode 109

Wes agreed to take the fall on his own for the bombing to protect his daughter and later tanked his parole hearing after Mathias showed up at the hearing for the same reason. Wes agreed to “gladly” serve more time to keep his daughter safe, but after an inmate attacked him in the prison van, he realized that Mathias wanted him out of the picture permanently.

“He wants me dead, so I want him dead. Time’s ticking, man. You want to help me? Help me kill him,” he told Alec. 

Alec convinced Wes that the only way to really protect Dahlia was to track her down themselves and keep her out of harm’s way, but just as they were about to set the plan in motion, Mathias called and told Wes to blow himself up or he would kill Dahlia in 38 minutes.

Using details from the photo of his daughter, including a distinctive covered bridge in the background, Alec, Phoebe, and Rizwan are able to determine her likely location. 

Wes set off a bomb inside Alec’s office to give Mathias the impression he killed himself and then Alec and Wes raced to save Dahlia.

The unlikely duo found her just in time, but before they could get Dahlia and her daughter to safety, a red dot sight from a gun hit Dahlia’s chest. Wes dove in front of her, taking the bullet meant for her in one final sacrificial act.

By the time authorities arrived, Mathias had already disappeared, but it seemed they may finally get the break they needed when Jace called Marisa and told her he had a new theory about Mathias’ identity that he wanted to tell her over breakfast. 

But when she arrived home, she found Jace dead from a gunshot wound to the chest.

How did they expose the church bombing plot on The Irrational?

The season finale began with Jace’s emotional funeral. Marisa told Alec she was convinced Sanford was somehow involved in the church bombing, since Jace had been looking into the possibility that one of his staffers on the cleanup crew had been the real target at the time of his death.

Of the three staffers who had been working that night, only one survived: a man named Roger Silmar. Simlar disappeared shortly after the bombing and was suspected to be in the CIA.

Alec’s girlfriend and former MI-6 agent, Rose Dinshaw (Karen David), was able to track Simlar down. He revealed that two nights before the bombing Sanford held a campaign event on a yacht for some of his biggest donors. That same night, Simlar saw Sanford, a notorious womanizer who was known to have frequent affairs, follow campaign aide Natalie Price into a back room. He followed them and discovered Sanford holding Price, who was passed out and foaming from the mouth.

Sanford later played the incident off, telling Silmar that Natalie had overindulged on some pills, but he gave her CPR and saved her life. However, Price was one of the staffers killed just two days later in the bombing.

Alec and Marisa realized that it’s more likely Natalie died on the yacht and the bombing was used to cover up her death, so that Sanford’s political career wouldn’t be derailed.

“Who would use a hate crime to cover up a murder?” Marisa asked.

 “When people feel cornered our moral code bends more than we or they could imagine,” Alec replied.

Sanford used an accomplice — the man known as Mathias — to arrange for the killing, but they had to figure out just who that man was. The stunning answer came after Phoebe and Rizwan snuck into Sanford’s office during a campaign event and found a photo of him with some war buddies.

The pair discovered from a security guard that Sanford was awarded the Purple Heart after taking out a machine gun nest and saving the men in his unit.

One of those men was the now-head of investigations at the FBI, Bob Caswith. They realized that Bob was using his ties at the FBI to not only find Wes and Peter, but to continue threatening them for years to keep their silence.

Marisa was rocked by the stunning betrayal after learning her boss and mentor not only orchestrated the bombing, but also killed Jace.

 “It all makes sense now, how Mathias manipulated Wes banning for all those years, how he found Wes’ daughter. Jace wouldn’t have thought twice about letting Bob in. He trusted him. I trusted him. The Bob I knew was an honorable man. He put his work first. How could he murder a fellow agent?” she asked.

Alec told her that Bob was likely torn between his responsibilities and felt he owed Sanford because he had once saved his life.

Marisa and Alec confronted Bob outside of the church, but just before he was about to give himself up, Sanford appeared and shot him in the back. Sanford tried to claim he shot Bob to protect Marisa and Alec and insisted Bob had acted alone without his knowledge.

They got Sanford to reveal his role in the plot, however, just before he was set to announce his run for president. It turns out, Sanford had slipped something into Natalie’s drink at the yacht party, not realizing she was allergic to opioids and then tried to cover up her death.

Through the use of Kylie’s clever computer skills, the confession was broadcast to the group of reporters waiting for the press conference to begin.

After 20 years the complex plot was revealed and Sanford was placed under investigation for his role in the bombing and Natalie’s death.

Originally published Feb 13, 2024.