The 118 and the 126 are teaming up for a life-and-death emergency.
The first responders of 9-1-1 and 9-1-1: Lone Star are teaming up.
The franchise stages its first crossover event next week, when members of the team from Los Angeles' 118 arrive in Austin to help the 126 fight an out-of-control wildfire in Texas that's heading dangerously close to the city. A dramatic promo teasing the two-part crossover premiered after Monday night's episodes -- and it looks like the 118 and the 126 are facing their biggest emergency yet.
According to Fox's official synopsis, the action begins on 9-1-1 when the crew prepares for their out-of-state mission. And when Lone Star begins, it's bad news when a wildfire starts spreading across Texas. Buck (Oliver Stark), Hen (Aisha Hinds) and Eddie (Ryan Guzman) arrive in Austin to help Captain Owen Strand (Rob Lowe) and the 126. As the crews try to save a group of teenagers trapped by the fire at a campground, Owen and Hen fight for their lives after the helicopter they're in crashes, leaving everyone scrambling to save them.
"What you waiting for, Hollywood?" Lone Star's Judd (Jim Parrack) ribs Eddie in the promo.
Watch the crossover promo below.
Though there was no official 9-1-1 crossover last year after Lone Star premiered, executive producer Tim Minear told ET that it was only a matter of time that one would come to fruition.
"I think it is inevitable," Minear said last March. "It's not unusual for firefighters from different states to join in. Firefighters from the United States went to Australia this year, so you never know where they might cross paths and you never know where a case or a story might cross state lines. We might be seeing some of the 9-1-1 crew in an episode of Lone Star if there's a season 2, just by virtue of a case."
The 9-1-1 and 9-1-1: Lone Star crossover event begins Monday, Feb. 1 at 8 p.m. ET/PT on Fox. For more on the franchise, watch below.
To stay up to date on breaking TV news, sign up for ET's daily newsletter.
RELATED CONTENT: