In the 22nd century, rising sea levels from global warming have wiped out coastal cities, reducing the world's population. Mecha, humanoid robots seemingly capable of complex thought but lacking in emotions, have been created. In Madison, New Jersey, David, a prototype Mecha child capable of experiencing love, is given to Henry Swinton and his wife Monica, whose son Martin contracted a rare disease and has been placed in suspended animation. Monica feels uneasy with David, but eventually warms to him and activates his imprinting protocol, causing him to have an enduring childlike love for her. David seeks to have Monica express the same love towards him. David is befriended by Teddy, a robotic teddy bear which belonged to Martin. Martin is unexpectedly cured of his disease and brought home. Martin becomes jealous of David, and taunts him to perform worrisome acts, such as cutting off locks of Monica's hair while she is sleeping.