The Killer Reserved Nine Seats

In Giuseppe Bennati's The Killer Reserved Nine Seats, an assortment of wealthy degenerates - including Italian cult mainstays Andrea Scotti (Django, Prepare a Coffin) and Howard Ross (The Pyjama Girl Case) - answer the summons of an eccentric nobleman (Chris Avram, A Bay of Blood) and assemble in the theatre attached to his ancestral home, only to find themselves trapped in the decaying building while a savage killer picks them off Agatha Christie-style!