Instead of Kevin (Justin Hartley) tying the knot with Madison (Caitlin Thompson), there was a five-year flash forward and viewers saw Kate (Chrissy Metz) getting ready to walk down the aisle to meet Phillip (guest star Chris Geere), who had previously hired Kate as a teacher's assistant.
The finale also saw Kate and Toby (Chris Sullivan) slightly at odds about his work-home life prior to the flash forward. In a segment taped before the finale aired, Metz appeared on The Tonight Show Starring Jimmy Fallon on Tuesday night, where she discussed the shocking twist.
"I've known for quite some time, Metz shared of the surprising ending. "I didn't know how it was going to unfold."
Metz, 40, who has been with the show since it premiered in 2016, noted that she was worried about how the finale would be received.
"I just, umm, I'm concerned for many people, including myself," she admitted. "I've known for quite some time and it's been hard, of course, to keep the secrets."
Metz even went so far as to compare the twist to another shocking moment in the series.
"It's close to Jack's (Milo Ventimiglia) passing. It's one of the bigger season finales," she shared.
It was recently announced that This Is Us will finish at the end of season 6.
Series creator Dan Fogelman discussed the surprising season 5 twist, sharing, "Chris is going to be a big part of the show next year... We owe a lot of him. He's an actor we've been following for a while and are big fans of on the show. It's obviously a plot point that we've known was coming for quite some time -- Kate's second wedding -- and we knew it would be revealed at the end of the season. We actually had Chris come down and meet with Chrissy much earlier in the season under severe testing protocols and everything so we could put them together and feel them out, because it was such an unusual season of shooting."