As we approach awards season, a lot of ink will be devoted to celebrating individual acting performances, but less will be written about the underappreciated virtue of cast chemistry, which is actually more vital to a film’s success. Case in point: No one will mistake Bill Hader and Kristen Wiig for Oscar-winning actors (at least, not at this stage in their career), but they make an irresistible duo in The Skeleton Twins as estranged twins trying to reconnect as adults. The years they spent together on Saturday Night Live have a palpable onscreen effect, and their close relationship feels entirely real because, well, it is.

Fans of their comedic TV work should not expect guffaws: The Skeleton Twins is a drama, and a dark one at that. The opening scenes find Maggie (Wiig) and Milo (Hader) each attempting suicide on the same day, though only Milo’s is successful enough to earn a hospital visit. After being released, he leaves Los Angeles and returns to his hometown to recover. Maggie and her dude-bro husband (Luke Wilson, who is better than ever) take him in, and the two siblings begin to get to know each other again.

In his first dramatic role, Hader succeeds enough in carrying the film, although he never uncovers much about Milo. Still, his unsuccessful efforts to reunite with his old high school teacher (Ty Burrell), with whom he had an illicit affair, are heartbreaking, and Hader handles these moments with a light, self-deprecating touch. He occasionally reverts to comedic caricature, but as his character’s a flamboyantly gay, out-of-work actor, caricature is not necessarily far from reality.

Wiig’s performance is more nuanced. Having settled into the role of the sibling who has her shit together, Maggie spends much of the film struggling to keep up her façade of contentment, a role well-suited to Wiig’s talents. Over the course of her young film career (which has included two other dramas, 2012’s Girl Most Likely and this year’s terrific Hateship Loveship), Wiig has come to specialize in characters with remote inner lives. Here, she challenges herself with a character whose suffering threatens to erupt at any moment, and it is her most complete performance yet.

Despite the cast’s commitment to the drama, it can only be considered a slight knock on the film that its most memorable sequences are those in which the old SNL castmates just get to be silly together. There is a cathartic lip-syncing sequence set to Jefferson Starship’s “Nothing’s Gonna Stop Us Now” that was wisely featured in the trailer. Another scene in which Maggie and Milo get high on laughing gas seems like an excuse for Wiig and Hader to improvise and giggle.

But really, who cares when these two leads are so great together? The Skeleton Twins may be an imperfect film of simple pleasures, but it is eminently watchable, and it serves as a testament to the ability of strong casting and good chemistry to save a movie from mediocrity.