Ostermontag (1991)

A twisted tale of obsession and mistaken identity unravels with shocking consequences. Heiko, consumed by his unreciprocated love for one of his stepsisters, is unknowingly entangled with her twin, Nicole, in a deadly game of deception. His growing confusion and frustration lead to a catastrophic error: the accidental murder of the wrong sister. Years later, Heiko, haunted by his past, lures who believes to be Nicole under false pretences, igniting a chain of violent and grotesque events of staggering proportions.