Guy Schermerhorn, brilliant young professor of psychology and disciple of the pioneering Dr Moncrieff, is making a name for himself on the talk show circuit with an unusual protege in tow: a chimp by the name of Sam. Sam lives in Guy's apartment, wears diapers and neckties, devours pizza and Macdonalds - and, through Guy's careful training, can communicate through sign language.

But living with Sam is wreaking havoc on Guy's personal life, and when shy, meek undergraduate Aimee Villard volunteers to take on babysitting for him, he can't believe his luck. Aimee and Sam have an immediate rapport, and before Guy knows it she's moved in, proudly devoting herself to Sam's care and Guy's project.

Aimee has never known purpose and happiness like this; but when Guy's funding is imperilled, and Sam is taken away by the sinister Moncrief, her world falls apart. Aimee discovers just how far she'll go to, and just what she'll risk, to be united with the chimp she's come to love so much.