After a terrible accident, young law student Allan (Jason Beghe) is left a quadriplegic. Confined to a wheelchair and overcome by depression and thoughts of suicide, Allan returns from the brink of despair when he meets beautiful young animal trainer Melanie (Kate Parker), who works for a program that provides people with physical disabilities with trained animal companions. Melanie pairs Allan with Ella, an adorable little Capuchin monkey who, unbeknownst to both, has been injected with human brain tissue. While Ella initially transforms Allan's life for the better, she soon starts to exhibit strange, possessive behaviour; and when those close to Allan start dying, he gradually comes to realize that Ella is telepathically channelling his own impotent rage and resentment and acting out his darkest impulses. "One of George Romero's most effective and interesting horror thrillers" (Jonathan Rosenbaum).