Dos aspirantes a cantantes suplantan a otros cantantes muertos que en realidad eran agentes secretos de incógnito y que debían actuar en una reunión secreta que se celebra en un misterioso castillo.

1973 film by Antoni Ribas

Chris Miller, living with her stepmother in a large secluded mansion, finds her isolation interrupted by the arrival of an unknown scythe-wielding killer.

it is still worth seeing, for two reasons: Paul Strand's beautiful pictures and Silvestre Revueltas' beautiful score.