Amanda's deathbed request to her son, John, was for him to destroy all the lab notes from her last experiment. She also blurts out he had a brother. At the funeral John meets Melissa, who claims to be his mother's biggest fan. Together with some of John's friends they go to Amanda's house, but none are prepared for what they find there: his monstrous, tentacled baby brother. Now he has to get to his mother's greatest advancement in Human Evolution before a mad scientist gets to him first.