On a rainy night professor Enzo Stefanelli coincidentally rescues the life of a young man who turns out to be a professional killer. In return for this gesture the killer promises him to kill any enemy of the professor. Against the professor's wishes, the killer sets off in search of a potential enemy in his environment and family, throwing the life of the professor into chaos. After initial skepticism Enzo opens up his eyes to his life and the people who surround him - Will Enzo be able to identify his true enemy? How will the killer, who has become Enzo's only friend, behave? And what if it would true that each of us has an enemy to be get rid off?