Sandra Demarest llega a la casa de los Caldwell y anuncia a su anfitrión, Mark, que estaba casada secretamente con su sobrino James, recientemente fallecido. Mark no la cree, pero le deja quedarse en casa mientras investiga sus afirmaciones. Julie, hermana de James, le cuenta a Sandra que ha escuchado unos extraños ruidos en el laboratorio de la casa. Llevada por la intriga, decide investigar qué ocurre en dicho laboratorio.
Hilary Fairfield returns home after fifteen years in an asylum with his sanity restored. But he is disturbed to find that everything has changed: his daughter grown and about to marry; his wife divorced and also about to marry.
Glen, a former sperm donor and recently diagnosed sociopath, takes his daughter on a murder spree of his sperm-donated offspring in the dark comedy, 'Spermicide.'