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When & How to Watch the Season 2 Finale of The Irrational Tonight on NBC

Which mind-boggling puzzle will Mercer solve next? Watch Season 2 of The Irrational on Tuesdays on NBC.

By Jessica White
Professor Mercer Teams Up with Bill Nye to Save a Stranded Astronaut | The Irrational | NBC
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Professor Mercer Teams Up with Bill Nye to Save a Stranded Astronaut | The Irrational | NBC
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Professor Mercer's Best Psychological Experiments | The Irrational | NBC
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Alec and Rose Sing a Deadly Duet | The Irrational | NBC
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The Most Dangerous Game | The Irrational | NBC
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Alec Sits Down with a Psychopath | The Irrational | NBC
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Professor Mercer Reveals a Shocking Truth | The Irrational | NBC
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Alec and Rose Witness a Deadly Hit-and-Run | The Irrational | NBC
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Can a Horse Be Guilty of Murder? | The Irrational | NBC
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Typicality Experiment Proves Memories Can't Always Be Trusted | The Irrational | NBC
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Dr. Mercer's Dad Shows How to Win Over a Wary Witness | The Irrational | NBC
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Female Magician Reveals the Greatest Illusion of All | The Irrational | NBC
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Dr. Mercer Steers an Interrogation by Downplaying an Angry Curator | The Irrational | NBC
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Marisa Shares Her Secret Origin Story | The Irrational | NBC
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How to Trigger a Toxic K-Pop Troll Using Behavioral Science | The Irrational | NBC
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Using Online K-Pop Drama to Explain Parasocial Relationships | The Irrational | NBC
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Mercer's Team Debates the Pros and Cons of Getting Soaked with Fish Guts | The Irrational | NBC
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Jesse L. Martin and the Cast Team Up for a Personality Quiz | The Irrational | NBC
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Professor Mercer Fakes a Favor to Befriend Victim's Ex | The Irrational | NBC

As Season 2 of The Irrational reaches a climactic end, fans are on the edge of their seats to see how Professor Alec Mercer (Jesse L. Martin) will navigate the mind-boggling challenges that await.

How to Watch

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

The Irrational Season 2 finale promises to be a riveting blend of psychological stress and action-packed intrigue as Mercer and his fearless friends tackle whatever mystifying case comes his way. Fans are sad to bid farewell to Mercer and his crew after they navigated some seriously juicy investigations and cases this season.

"There are so many possibilities when it comes to just concentrating on how we think and how we behave," Martin told Collider. "Mental health is a big topic on everybody's platforms these days, and our show explores it, certainly in a scripted context, but in so many different ways with so many different people. The more interesting actors we get in, the more that behavior surfaces... There are so many places to get creative. There are so many stories that can get told when you're just talking about behavior, in general."

RELATED: All About Influencer Collins Key's Cameo on the Irrational

Learn when and where to watch the finale episode of The Irrational Season 2, below.

Alec and Kylie talk to a man in The Irrational Season 2, Episode 9.

Is The Irrational new tonight, March 25, 2025?

Yes! And it's set to be a gripping Season 2 finale.

The synopsis for tonight's episode of The Irrational Season 2, Episode 18 ("The Exchange") — reads: "When Alec is recruited to assist with a multi-national prisoner exchange that has gone awry, he sees an opportunity to rescue a wrongfully imprisoned colleague; the case pulls Alec and Rose into the dangerous world of international espionage."

Alec Mercer (Jesse L. Martin) in Season 2 Episode 1 of The Irrational.

When can you watch The Irrational Season 2 finale?

The Irrational Season 2 finale airs on Tuesday, March 25 at 10/9c on NBC.

Alec Mercer (Jesse L. Martin) and Rose Dinshaw (Karen David) embrace in a warmly lit living room in The Irrational Episode 217.

Where can I watch old episodes of The Irrational?

Every episode of The Irrational is available on Peacock, NBC's streaming service.

RELATED: Before The Irrational, Ron Canada Worked with Jesse L. Martin on Law & Order

"We are so lucky and privileged to have Jesse Martin playing the role of Alec," The Irrational showrunner Arika Lisanne Mittman told NBC Insider. "When I first wrote this character, there was a character I wrote on paper, and there's what Jesse brought to it, and those two things put together have just created magic, and I'm so grateful to have him. He's wonderful to work with. He's really a gift to all of us."

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