Primate

The film opens with a veterinarian being killed by a chimpanzee at a remote Hawaii property. The story rewinds 36 hours: Lucy returns home from college with friends Kate, Hannah, and a handful of others. The household is her deaf father Adam, her younger sister Erin, and Ben — an adopted chimpanzee who uses a soundboard to communicate, a system Lucy's late mother built with him. Ben greets Lucy with the teddy bear she gave him as a child. He remembers.

Adam finds a dead mongoose in Ben's enclosure and realizes Ben was bitten by it. Before he can have it tested, the vet Lambert arrives to check on Ben — and Ben kills him. Rabies. Ben is loose. The group retreats to the pool, where Ben's hydrophobia keeps him at the edge, stalking the perimeter. Nick tries to push Ben off a cliff. Ben throws him off instead. They spend the night on a pool float, waiting for daylight.

Dawn doesn't bring safety. Ben crushes Kate's head with a rock. Drew is killed in the house. Brad is beaten to death with a shovel. Hannah manages to get a 911 call out before Ben mauls her in a car.

Adam comes home to find the carnage and finds Lucy and Erin still alive. The three of them fight Ben together — the father, his daughters, the animal they raised. Adam stabs Ben with a broken wine bottle. Ben goes still. They hold each other.

Ben attacks again. He and Lucy go over a balcony together. Adam catches Lucy. Ben hits a broken chair leg below. Police arrive. Erin is hospitalized. As the family processes the wreckage, an officer accidentally triggers the soundboard. It plays: Lucy bad.