"No One Heard the Scream" has many of the tropes of a mystery, or even giallo, film. However it largely eschews these genres for most of the run-time, creating less a genre film than a twisted drama about two people pushed to the edge of experience.
The protagonist is an expensive mistress for rich men who witnesses her neighbour disposing of his wife's body. The neighbour takes her hostage and the duo go on a trip to the ocean to dump the body in the sea.
Along the way, the movie loses its original thriller-aspect and becomes a drama about two people in a strange situation. The actress, particularly, is a problem, so cold and inert. When the movie makes its predictable, if belated, detour into homoeroticism with the introduction of an unnecessary nephew of hers, it's almost a relief to see something on screen other than hardened, impassive faces.
There is a romance that feels unlikely and forced, and you are forced to make the conclusion that the openly gay Eloy de la Iglesia just wasn't comfortable shooting romance, love or eroticism between men and women.
Perhaps this extended to his casting of the female lead. She looks like someone who was probably a knockout about five years ago. Would men who can afford to keep an expensive mistress use someone her age?
Then there is a conclusion, which is also a little hard to swallow, and smacks of the tawdry plot developments we got from the giallo genre. It seems like the movie is doubling back on itself, forgetting the progress it made as an interesting drama, and saying "See! This was a thriller, after all!"
I don't know if de la Iglesia ever really made genre pictures; even "The Cannibal Man", notorious Video Nasty though it may be, was perhaps equal parts drama. It also featured an unnecessary young male character as a source of homoeroticism.
Perhaps de la Iglesia, who was a superb filmmaker, needed to be encouraged to make dramas and leave behind genre tropes. For the rest of his career, that's what he seemed to do, thankfully.