Zach Galifianakis’ irreverent web series is the latest TV show to receive the big streaming treatment. “Between Two Ferns: The Movie” premieres Sept. 20 on Netflix. The official trailer dropped Tuesday, promising a flick that’s two parts talk show and one part Judd Apatow-adjacent road comedy.

The star-studded clip begins with Matthew McConaughey being interviewed by Galifianakis on a set while sitting between the titular two ferns. The interview quickly fizzles out in a geyser of water from a broken pipe, which kills McConaughey — though only “momentarily,” according to Will Ferrell, who offers Galifianakis a shot at redemption.

The former “Saturday Night Live” star offers him the chance to host his own talk show if he can “complete a series of high-profile celebrity interviews,” per the Netflix synopsis.

“I’m a white man,” quips Galifianakis, “and I’m straight and I deserve it.”

From there it’s off to the races, as Galifianakis tours the US with his merry band of misfits, encountering a who’s who of celebrity cameos, including Paul Rudd, Chrissy Teigen, David Letterman, Peter Dinklage, Brie Larson and Benedict Cumberbatch (or “Beenad - - k Cumberbutt,” as Galifianakis mockingly refers to him).

It’s hard to imagine that an “unscripted talk show” where a comedian trolls celebrities Sacha Baron Cohen-style (albeit celebrities who are aware of the format) with a barrage of barbs, non sequiturs and all-around-awkward questions on the most Spartan set can be Tetris’ed into a three-act feature-length film. It seems as Sisyphean as playing Rachmaninoff on the washboard.

Here’s hoping Galifianakis can square that circle.