It’s almost poetic that “Send Help” — the new film from director Sam Raimi — mostly takes place on a deserted island.

In a month when major studio releases tend to be more miss than hit, “Send Help” is in fact on an island of its own. It’s a dark and twisted tale of survival with Raimi’s unique eye behind the camera and performances from leads Rachel McAdams and Dylan O’Brien that pull no punches.

McAdams plays Linda Liddle, a socially awkward strategy analyst working for a big corporation who lives alone with her bird with dreams of being a contestant on the TV show “Survivor.”

Linda’s new boss Bradley (O’Brien), taking over for his recently deceased father, overlooks her for a previously promised promotion, giving her one chance to prove herself on a business trip to Bangkok. When the plane crashes and Linda and Bradley are the lone survivors, Linda gets the chance to put her survival skills to the test. The results are a back and forth battle for control between Linda and Bradley that grows increasingly dark — and at times very, very uncomfortably funny.

The script from Damian Shannon and Mark Swift is full of surprises both in the way the story unfolds and the way these characters increasingly grow more and more complex. “Send Help” straddles the line quite effectively, as the audience starts to realize that this is a mental game of chicken in which neither person comes away innocent.

Raimi, tackling horror for the first time since 2009’s “Drag Me to Hell,” shows that he still has his fastball. The film finds a nice balance in tone, going from gross out and gotcha moments to some dark humor that doesn’t feel forced or out of place.

Perhaps Raimi’s best feat as the director is allowing his two leads to just go nuts. O’Brien can go from sexist boss you want to see get his comeuppence to a sympathetic victim that might be trapped on an island with someone who makes Kathy Bates’ character in “Misery” look like Mary Poppins in a snap. And in both instances he comes across quite believable.

But it is McAdams who is the heart and soul of “Send Help.” Without her work it would be hard to believe this timid employee could in fact be capable of some rather heinous and underhanded things. McAdams makes Linda’s transformation on the island effective, at times almost feeling like she is playing multiple characters the way she is able to capture the complexities of her character.

It all builds to a devilishly dark finale that only someone like Raimi could pull off. Even if the final twist might be obvious, it is still a fun ride to get there with McAdams, O’Brien and Raimi all at the top of their respective games.

Grade: B