Film editor Rey Ciso works on cutting director Francesco Mancini's latest ''giallo''/''poliziotteschi'' film ''Tarantola'' with his beautiful assistant Bella. Once an acclaimed, up-and-coming editor, Rey lost his right-hand fingers in a freak accident and is now handicapped by a prosthetic wooden hand. After hours, an unknown killer sneaks into the studio and kills lead actor Claudio Calvetti and his girlfriend Veronica while they view a workprint of the film. Actress Margarit Porfiry stumbles upon Veronica's hanging body and is stricken with hysterical blindness. Her husband, Police Inspector Peter Porfiry, interviews studio employees.