Sin City Ultra presents a dark journey into a deranged universe of pure evil and absolute decadence where bizarre, unspeakable acts are the rule and innocence is just a vague memory. Hank Crane, a rich producer is throwing a party for his young wife and chooses an infamous, abandoned mental hospital for the festivities. The Cranes have invited their most twisted friends for a night of fun, frolic and sin. Everything is set...until one by one the guests begin to change as they slowly succumb to a strange dark lust from somewhere in the house....