The inmates of an insane asylum take over the institution, imprison the doctors and staff, and then put into play their own ideas of how the place should be run.

Tancredo, a poor man, is in love with a rich girl, who does not return his feelings. One day when she is bathing in a river, a flood sweeps her away and Tancredo is unable to save her. Mad with grief, he steals the sun. The gods call Apolinar to restore light to the earth, but he is obstructed by the magician of darkness, until by means of a telescope he is able to send a bag of light to Tancredo, now grown old. Tancredo goes to the seashore and opens the bag of light as an offering to his beloved, whereupon the sun returns to the earth.

Bruno Halder a sinister scientist seeking revenge against his brother and niece is resurrected by Waldo his faithful sidekick. Besides his minions of zombies Halder enlists the help of Wolfman, Franquestain, a Vampire, a Mummy and a Cyclops. Once again the survival of mankind is put in the hands of Santo