Kristen Wiig and Bill Hader, two especially talented ex-“Saturday Night Live” cast members, reunite in the funny and sad “The Skeleton Twins.”

Wiig and Hader play a pair of troubled adult twins who haven’t seen each other in a decade. Their “SNL” chemistry reignites, snapping like clockwork.

Co-writer and director Craig Johnson, in just his second feature film, and writer Mark Heyman (“Black Swan”), provide Wiig and Hader with a multi-dimensional, entertaining, affecting story centered upon the deftly defined twins.

In addition to Wiig and Hader’s comedic work in “The Skeleton Twins,” the movie goes to dark places. It modulates from amusing to tragic without so much as a speed bump.

Hader plays Milo, a gay waiter in Los Angeles whose dream of being actor went sour. Wiig’s Maggie remains in upstate New York, where she has a cheerful but wary husband.

Milo’s suicide attempt sets the siblings’ rocky reunion in motion. Maggie being his next of kin, the hospital phones her at a pivotal moment in her own life. In the later clever moments, the filmmakers let the audience know how unhappy both brother and sister are.

Maggie, pushing distance and estrangement aside, flies to her brother’s beside in L.A. During their soft conversation there, Milo tells Maggie he was just drunk and melodramatic. “You shouldn’t have come here,” he says. “You should go.”

Maggie invites her suicidal brother to stay with her in New York. He balks. “They guilted you into this,” he says.

Milo agrees to visit Maggie, who’s still residing in their hometown. She and her husband, Lance, welcome him and quickly confide that they’re trying to conceive a child.

“Keep trying guys,” the subversive Milo says. “I can’t wait to be the creepy gay uncle.”

When Hader applies the word “creepy” to himself, he flashes traces of the hammy mock menace he displayed during his “SNL” years.

The comedy in “The Skeleton Twins,” in general, gives him and Wigg rich terrain in which to exploit their comedic gifts. A few scenes play like “SNL” clips.

All the while, “The Skeleton Twins” tells a genuinely dramatic story about a brother and sister who’ve been dancing on the edge since childhood. Wiig and Hader are up for it. Luke Wilson, too, as Maggie’s husband. Wilson plays all the right notes as the warm, loving, if average, husband who’s grown anxious about the landmines his wife plants under his innocent feet.

“The Skeleton Twins” dispenses some back story as Maggie and Milo trip along. In a testament to the film’s depth of characterization, there’s a lot to learn. For one thing, suicide runs in the family.

But the film’s occasional, fragmentary flashbacks to Milo and Maggie’s childhood could have been left out.

The story’s present-day events fully reveal that the troubled twosome is chronically tangled in the past.

“The Skeleton Twins,” despite a resolution that doesn’t match the storytelling that preceded it, is one of this fall movie season’s indie films to see. A trio of filmmakers with New Orleans roots — executive producers Mark and Jay Duplass and co-producer Stephanie Langhoff — brought this deserving-of-an-audience project to screen.