Regardless of how you felt about the ending, there is no denying that Lost is one of the most iconic shows of all time. With a striking pilot that cost over $14 million (the most in television history) and a rich, prolific mythology, Lost continues to be a much talked-about, much-debated show, even five years after its finale. So which influences do we have to thank for helping create such a juggernaut of a series? According to writer/co-creator Damon Lindelof, Saw 2.

Apparently, the inspiration for the climactic twist at the end of season 3’s finale, “Through the Looking Glass,” was born from a viewing of the sequel to the popular torture-porn movie. For those in need of a reminder of the plot of Saw 2, Lindelof explained it to BuzzFeed News:

If you have not seen Saw 2, all you need to know is that Donnie Wahlberg is in it and that the twist at the end involves tricking the audience into thinking they’re watching something unfold in present time, when in fact it is unfolding in the PAST. Also, Donnie Wahlberg is in it.”

If you’re still wondering how these two pieces fit together, in “Through the Looking Glass” it’s revealed that the supposed flash-backs of Jack at home in L.A. are flash-forwards (we see him waiting for someone at LAX and island mate Kate steps out of the car). In addition to being Damon Lindelof’s favorite scene he’s written for the series and an important turning point for the show, that moment will also be remembered for ruining the phrase “We have to go back” forever. But as much as that scene may mean to fans, it means even more to its creator.

“I was inside the thing… feeling what these characters were feeling…knowing we were, at long last, working toward an actual ENDING now,” Lindelof said. “And finally… for one fleeting moment… I felt peace.”