Is there anything better than watching a filmmaker operating in their element? Not going through the motions, mind you, but genuinely unleashed, deploying every trick they’ve spent decades perfecting? Send Help is Sam Raimi at his most unhinged and joyful, a gleefully nasty survival thriller that marks his first R-rated horror since The Gift in 2000. After six years in development, Raimi (Drag Me to Hell) has assembled the perfect cast and crew to deliver something vile, cruel, hilarious, and absolutely irresistible.

Linda Liddle (Rachel McAdams, Spotlight) is an overlooked employee in her company’s Strategy and Planning department, promised a promotion by the late CEO that his trust-fund son Bradley (Dylan O’Brien, Twinless) has no intention of honoring. When their plane crashes en route to a merger meeting in Thailand, Linda and Bradley become the only survivors, stranded on a deserted island. She knows survival. He knows corporate politics. Neither skill set is going to make this easy.

Writers Damian Shannon and Mark Swift, who previously collaborated on Freddy vs. Jason and the 2009 Friday the 13th, have delivered a script that keeps you guessing whose side you should be on. Bradley is obnoxious in ways that make your skin crawl, from his grating nasal laugh to his reflexive dismissal of anyone he considers beneath him. O’Brien commits to making him insufferable for as long as possible. But here’s the thing: he’s being held captive by Survivor-fan and trained outdoorswoman Linda, who discovers her true calling living off the land. Should we root for him? McAdams makes Linda so bonkers, so appealingly deranged after years of being beaten down by the Bradleys of the world, that when she goes full Annie Wilkes, there’s empathy mixed with the horror.

This is McAdams’ show, and everyone on set knows it. She’s rarely been so relaxed and free to go wild, and Raimi rewards her with shots that make her look stunning even caked in dried blood and mud. The drag-out finale is excellently staged and scored. O’Brien, coming off an impressive run that includes Saturday Night, Caddo Lake, and Anniversary, proves he can play smarmy just as well as sympathetic.

All the classic Raimi-isms are present: gross-out humor, fast-moving action, lots of viscera, projectile liquids flying into mouths at the worst possible moments (repeatedly), and yes, a Bruce Campbell appearance that fans will appreciate. Cinematographer Bill Pope gives the film a bright, airy look that contrasts deliciously with the mayhem. Danny Elfman‘s score initially seems discordant but makes perfect sense as the film progresses, matching its quirky, demented charm. Editor Bob Murawski keeps things moving at a clip that makes the nearly two-hour runtime fly by.

January has historically been a dumping ground for studio leftovers. Not anymore. Send Help is quality work from a master, a film that works for any time of day and deserves to be seen with a crowd. You’ll be laugh-screaming or scream-laughing, depending on how Raimi wants to approach his moments of shock. Either way, you’re going to have a great time.