OK. Despite the Lovecraftian pedigree, what we really have here is a cheap horror potboiler: Stuart Gordon's Attack of the Fish People. I swear that's not a bad thing. Dagon never works up the impressive head of steam that's required to make this sort of picture really shine - and the CGI work ranges from bad to worse - but Gordon's affection for his actors remains in welcome evidence, and for the first time in many years, he manages to deliver the shocks, if not the scares.

The film starts out at sea, with irritating yuppie Paul (Ezra Godden) and his feisty wife Bárbara (Raquel Meroño) on some kind of yacht holiday. A freak storm off an old Spanish shoreline runs them aground, and when Paul heads into a nearby fishing village, Imboca, for help, creepiness ensues. The men in town have webbed fingers and seem startled by his presence. Scary dudes shuffle down alleyways like refugees from a Romero zombie movie. The hotel room seems not to have been occupied in years, and the desk clerk, well, the desk clerk has gills. And, hey, where the hell has Barbara disappeared to, anyway?

After this splendid set-up, Dagon suffers mainly from a distended second act that bears the hefty burden of exposition. (Yes, backstory is important, but let's have no more of it delivered in lengthy flashbacks narrated by the friendly old man conveniently located by the protagonist, OK?) With the history of Imboca firmly established - and once Paul stumbles across a woman there (the big-eyed Macarena Gomez is a find) who has haunted his dreams - the story moves forward to its nasty conclusion.

Given the downright conservative tone of most horror films lately, the ripping and raping that caps Dagon's leisurely build is itself startling. Replete with gore and nudity, the final reels make it to giddy exploitation territory. In one scene, the hero starts reciting the Lord's Prayer as a ritualistic murder takes place before his eyes, but his words are choked off as the bloody spectacle escalates. It's a knowing B-movie flourish in a film that's full of them.