Chicago Fire fans were thrown for a loop in the season 12 finale on May 22, 2024, when Kelly Severide found out he had a secret half-brother, as they share the same dad, Benny Severide. Inside how the plot twist came about and what’s in store for the characters.

Who Was Benny Severide on ‘Chicago Fire’?

Benny was Kelly and Katie Severide’s father. He was a former captain in arson investigations. The actor who portrayed him, Treat Williams, died at the age of 71 in June 2023 after being involved in a fatal motorcycle accident near his home in Vermont.

Kelly, played by Taylor Kinney, was a product of Benny’s marriage to Jennifer Sheridan. Benny ended up leaving his wife and son after cheating on Jennifer with a teacher at Kelly’s school.

Who Is Benny Severide on Chicago Fire Half Brother Spoilers
NBC

Katie, played by Brittany Curran, was the product of a Benny’s relationship with another woman, and he didn’t see his daughter for more than two decades. He later remarried and became the father of two stepsons.

The character of Benny suffered a stroke and died in season 7 of Chicago Fire.

Who Is Benny Severide’s Secret Son Jack Damon?

Damon, played by Michael Bradway, was introduced as a new firefighter at Station 51 on the last episode of season 12. He had a mysterious phone call on his first day, saying “That isn’t the only reason why I’m here,” to an unknown caller. Damon added, “No, no, nobody here knows. And I’ll keep it that way for as long as I want.”

After getting the cold shoulder because of the call, Damon assured the squad that it was of a personal nature and not about the firehouse.

Damon took an instant interest in Severide, who thought he might be a good addition to the station.

Who Is Benny Severide on Chicago Fire Half-Brother Spoilers
KAMIL KRZACZYNSKI/AFP via Getty Images

While on the scene of a restaurant fire, Damon, Stella and Carver encountered a dynamic featuring a possibly abusive father and older brother and an injured younger brother. A fight erupted, drama ensued. and it caused Damon to later reveal his big secret to Severide.

“I wanted to answer the question that you asked me last shift. About why I lost my cool on that call and why I really came to 51,” Damon explained. “That guy at the restaurant, the father, he was being mean and he was treating that younger kid like dirt. And I had a father like that, too…”

Damon then dropped the bomb, “His name was Benny Severide,” as a look of shock came over Kelly’s face and viewers will have to wait until season 13 to find out what comes of the big revelation.