It's not easy pulling of a psychological terror movie. Probably even more difficult on a low budget. And Siren seems to be done on a bare-bones budget. There are a total or 6 actors or so in the entire movie and only a few locations. That said I'm glad it was filmed on location on an island and not in a studio.
The story involves a couple in lust, Ken and Rachel who take a trip on a boat around the Greek islands. For some reason, Rachel's ex comes along for the trip. As they get close to an island they encounter a skinny man bleeding out of his ears and who ends up dying shortly after that. They bury him on the island and run into a strange woman who doesn't speak much.
That's when the psychoterror begins as all the tourists start seeing and hearing things, although none of it is particularly scary or threatening. At first what keeps the movie going is the sexual tension between the attractive ladies Rachel and the woman. Once that fades away, the movie quickly goes downhill as the psychoterror ramps up and becomes more dull and pointless. Countless times we have one character wondering off into the woods and everyone else screaming his/her name over and over.
The title gives away what this movie is about and yet they try to present that as a surprise, it obviously isn't. They should have given this movie a different title. Also important is a little background mythology and explanation the strange woman gives- which ends up in the deleted scenes! There is a final twists in the movie which was very good and made things interesting.
Despite the low budget, this movie looks very good, the ladies are hot, but the story is too minimal. Even though Siren is fairly short it feels long because nothing serious goes on. A well made movie that is seriously hampered by a weak script and lack of ideas.
