Photo: HBO

[Warning: This post contains plot points from the final season of The Leftovers, which, if you haven’t watched yet, you should really get on.]

It started off as a little joke in season one: The entire cast of ’80s sitcom Perfect Strangers had vanished in the Sudden Departure. As The Leftovers showrunner Damon Lindelof explains in a new video interview with Vulture, it was just the kind of goofy, tossed-off joke that helped lighten the oppressive mood that suffused many of the show’s stories.

And, in season two, the writers decided to up the ante, asking actor Mark Linn-Baker if he’d be willing to participate in a new wrinkle on the story—namely, that “Mark Linn-Baker” had faked his disappearance in the world of The Leftovers. The actor was game, and spent a day shooting what ended up being about five to 10 seconds of screen time. But in season three it really became a key plot twist, as Baker’s depressed actor turns out to be the one to meet with Carrie Coon’s Nora, and explain to her that there’s a machine that could reunite her with her departed family.

The A.V. Club interviewed Baker about his experience, getting the actor’s perspective on the story, but here Lindelof explains the motivation behind having Baker become an active player in the narrative of the show. Essentially, it came down to believability, weirdly enough. Nora would find the entire idea of a machine that can transport people to the world of the departed completely ludicrous, so “if the person presenting this crazy idea to her is equally absurd, maybe two negatives equal a positive? Maybe it actually makes it seem more reasonable.” Hey, their meeting didn’t take place onboard a lion sex orgy boat, so it’s already in the realm of more reasonable.