《我欲为人》讲述了三个超自然生命体吸血鬼、狼人和鬼魂机缘巧合地住在了同一屋檐下的故事。三人都暴露了各自的秘密，于是他们决定和平共处，在人类的世界努力生存。在美版中，山姆·威特沃将饰演吸血鬼Aidan，Meaghan Rath则是鬼魂Sally，来自演员世家的萨姆·亨廷顿则饰演有些神经质的小狼Josh。而《邪恶力量》中饰演Lucifer的马克·佩雷格里诺则饰演Aidan的导师Bishop。Aiden (a vampire) and Josh (a werewolf), move into a new house together to try and live normal lives. They didn't however know that they would end up with a third supernatural roommate as well. That's when they meet Sally the ghost. The three supernatural creatures go through various adventures together constantly protecting one another like family.