'9-1-1' Cast Teases Season 3 Finale, Plus Abby & Buck Reunite (VIDEO)

Meredith Jacobs

What better way to end a season that started with a tsunami than with a massive train wreck that also reunites exes?

The 9-1-1 Season 3 finale takes the 118 to the scene of the derailment teased at the end of the penultimate episode. TV Insider has an exclusive behind-the-scenes look at "What's Next?" and scoop from the cast.

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'9-1-1's Penultimate Episode Puts Athena & [Spoiler] in Danger (RECAP)

Maddie received two important 9-1-1 calls in 'Powerless.'

"We are definitely going to be in the trenches of heightened danger," Aisha Hinds previews, adding, "in the finale, fans can definitely expect to feel the myriad of emotions that they feel throughout the season."

Watch the video above for more from the cast, a look at the train derailment, and Abby's (Connie Britton) return — and reunion with Buck (Oliver Stark).

Oliver Stark Ryan Guzman 911 Season 3 Finale Buck Eddie

(Jack Zeman/FOX)

The penultimate episode closed the book on Athena's (Angela Bassett) serial rapist case and ended with a look at this major accident. In fact, it was Abby who called it in to 9-1-1, and Maddie (Jennifer Love Hewitt) answered, marking the first interaction between Buck's sister and his ex-girlfriend.

"Everybody in the finale gets a moment and gets some things wrapped up, but there are certainly moments within the train derailment itself that really have Buck considering the direction that he's going in," Stark previously teased. "There's also some happy moments for some other characters that are going to shake things up moving forward in Season 4."

9-1-1, Season 3 Finale, Monday, May 11, 8/7c, Fox