Athlete Allan (Jason Beghe) becomes quadriplegic after a horrific traffic accident. His friend Geoffrey (John Pankow), who is conducting experiments with monkeys, offers Allan a well-trained monkey named Ella to keep him company and raise his spirits. But the initially healthy bond, which even enables Allan to form a romantic relationship with Melanie (Kate McNeil), gradually disintegrates once Ella begins to channel Allan's underlying rage and takes it out on his loved ones.