Sweet and demented don’t often go hand in hand, but in James Sweeney’s second feature, Twinless, they are a match made in cringe comedy heaven. Written, directed, and starring Sweeney, with a brilliant turn from Dylan O’Brien, the film starts out as a sweet dramedy until the opening credits roll, an ominous 20 minutes in.

After a car crash kills his identical twin brother, Rocky, Roman (both men played by O’Brien) is having a difficult time adjusting to being an only child. Realizing his anger is a problem he heads to a support group for grieving twins where he meets Denis (Sweeney), an unassuming gay man who is mourning his twin, Dean. 

Seeing some of Rocky in Denis, Roman reaches out and the two form a bond, eating sandwiches in diners together and going grocery shopping. Roman does most of the talking, explaining why he and his twin weren’t close and remembering the things he misses about him. The relationship that forms between a man so straight it’s almost cliche and an out gay man isn’t like any we’ve seen onscreen before. But it is the endearing bond between Roman and Denis established in the first half hour that holds the film together when things get increasingly uncomfortable and more morally gray.

I don’t want to reveal too much but Denis’ motivations are anything less than pure — they are almost predatorial. I do feel comfortable saying he knew Rocky in a sexual capacity. As we learn more about his past and mental state, the focus shifts away from Roman and onto Denis. At times, it feels like the two are in very different films. Sweeney is more suited to a Mike White/Tim Robinson/Emerald Fennell kind of comedy while O’Brien is firmly in a dramedy space (think like 50/50, The Farewell, or This is Where I Leave You). Both shine in their perspective genres, though O’Brien is clearly at the top of his game here. As Rocky, he rocks a Freddy Mercury-like swagger complete with a mustache and a flouncey strut. As Roman, he brings out a sensitivity to what could be a dumb-jock role. In the latter performance, you just want to hug him until 

When the other shoe finally drops, Sweeney takes his time with the fallout, making you question how — and if — he will stick the landing. He certainly stumbles and the climax can’t live up to the build-up, but everything about this concept, from the broadest level to the smallest micro-joke, feels interesting and daring. His first film, Straight Up, felt this way as well but didn’t cross into the taboo as this one does. 

Try to go into Twinless as clueless as possible. The twists Sweeney leads you on are a flipping ride and you don’t know where or what the next turn is. Though, at times there’s a tonal clash between O’Brien’s numb Roman and Sweeney’s almost surreal portrayal of Denis, their different approaches pay off in the end and prove the latter is a filmmaker to watch.

Twinless premiered at Sundance this week and will compete in the U.S. Dramatic Competition. It will be distributed by Paramount’s Republic Pictures. A release date has not been announced.