It is the story of a terrorist who manages to escape during a transfer by sea and lands on a remote desert island where there is a large mansion inhabited by a little girl about 9 years old a girl of 18 and their housekeeper.
The Tiber Island rises in the center of Rome and it was also a witness of the "Black Saturday", the Nazi raid of 16 October 1943. Today that terrible night can resurface to remind us that without memory there is no future.
Piraña is a ruthless drug dealer who the police are unable to stop and who the city (with its roads, streetlamps, cemetery and city bus service) one night decides to punish with a long and terrible nightmare.
A former circus artist escapes from a mental hospital to rejoin his armless mother - the leader of a strange religious cult - and is forced to enact brutal murders in her name as he becomes "her arms".