9-1-1 season 10, premiering October 15, 2026, will continue exploring the fallout from the season 9 finale, which saw Buck's friends Connor and Kameron die and left him taking in their son, Theo. Buck became the couple's sperm donor in season 6 while they were trying to conceive, resulting in his biological son Theo. Though Buck had not previously been part of the boy's life, the end of season 9 set up Buck fostering Theo and stepping into fatherhood for the first time.
The season 9 finale capped off a difficult stretch for Buck, who spent much of the previous season helping his fellow first responders grieve after Bobby's death in season 8. Now, with Theo in his care, Buck faces navigating the foster system, much as Hen and Karen did in earlier seasons, while adjusting to putting a child's needs before his own. Buck has experience with kids through his relationships with Eddie's son, Christopher, and his niece, Jee-Yun, but the show is drawing a distinction between helping raise a child and raising one of his own.
That challenge is expected to draw Buck and Eddie even closer, with showrunner, co-creator and writer Tim Minear confirming that Theo will "absolutely" bring the two nearer together. Season 9 already leaned into visual and narrative parallels between the two characters. When Eddie discovered Connor and Kameron unconscious in a car during a bridge pile-up, he tried to shield Buck from the scene — echoing what Buck did for Eddie in season 2 after Eddie's ex, Shannon, was hit by a car. Minear addressed the parallel directly in an interview with Decider: "That was intentional. It was also what would happen in the scene. But it was intentional. I was very aware of that parallel. There's also another parallel in that scene. When he takes Theo to the ambulance, he intentionally turns him away from the scene, which is exactly what he did with Chris in the tsunami when the dead bodies were floating by. There are parallels to [Buck and Eddie's] stories. There's nobody that would know more about what it's like to be a single dad raising a kid than Eddie, so that's convenient."
The show has long hinted at more between Buck and Eddie. In season 4, Eddie told Buck he had changed his will to name Buck as Christopher's guardian if anything happened to him. The two have also functioned as co-parents to Christopher for years. 9-1-1 has a history of centering long-term romantic relationships alongside its first-responder storylines, including Bobby and Athena before Bobby's death, Hen and Karen, and Maddie and Chimney.
Photo: Gage Skidmore from Peoria, AZ, United States of America, CC BY-SA 2.0, https://creativecommons.org/licenses/by-sa/2.0, via Wikimedia Commons
