Connie Britton Returns in Dramatic '9-1-1' Season 3 Finale Promo

9-1-1 fans are in for a treat with the series' Season 3 finale. The FOX series' season finale isn't just going to be full of drama and action-packed sequences, it's also set to feature a familiar face. Connie Britton, who previously portrayed Abby Clark on Season 1 of the drama, will be making a grand return in the two-part Season 3 finale, which will air on Monday and May 11. And in a preview of 9-1-1's Season 3 finale, it appears as though Abby is involved in quite a scary situation.

In the Season 3 finale, many are in peril following a disastrous train crash. The incident even puts one of the series' main characters, Athena (Angela Bassett), in danger, based on the preview that the show shared following the Monday night episode. Britton's Abby is front and center in the promo, as she can be seen calling in to report the accident. "There's been a train crash," Abby says as she calls in to report what's going on around her. "This is a mass casualty situation."

Prior to Britton's return to the series, Entertainment Tonight spoke with 9-1-1 star Oliver Stark, whose character, Buck, was previously romantically involved with Abby. When asked about whether Britton could return, and whether there is any unfinished business between their characters, Stark did touch upon the subject.

"My character goes on this kind of journey to reunite an older firefighter with his lost love [in episode 16] and it kind of brings up some feelings and makes him kind of question where his head is at with his life," Stark told ET in early April. "And, you know, it could possibly set up someone returning -- whether that is a good thing or a bad thing — or does it need to be properly crossed."

As previously mentioned, it's been some time since viewers have seen Britton's Abby in action. At the end of Season 1, Britton left the FOX series, with Abby choosing to travel the world. Before she did exit the show, the former Nashville star had nothing but great things to say about her time on 9-1-1. In advance of the show's series premiere, she even spoke about what made playing Abby so interesting.

"It is a tough balance but very interesting," Britton told Dispatch, in regards to the fact that her character has to keep her emotions in check while on the job. "With every role I play, I want to feel like I am doing something that I haven't done before. I always look for what the challenge is going to be and what the risk is going to be."