Way back in the 1940s, Martha Beck, a once-divorced mother of two children from two fathers, advertised in the lonely hearts sections of the paper. It was answered by Raymond Fernandez, a suave ladies man who had abandoned his wife and children in Spain. Fernandez claimed to use black magic to make himself completely endearing to whatever woman he calls on. Then, he would wine them and dine them, then steal their money. When Beck and Fernandez met, they fell into a parasitic symbiosis where Fernandez would wine and dine the women and Beck would kill them after he got the money.

This lurid tale of sex, money, and death has been mined for cinematic glory on multiple occasions, perhaps most famously in the 1969 film The Honeymoon Killers. The plot is so familiar to audiences that it was essentially stolen for Mike Myers’ under-appreciated So I Married an Axe Murderer, a satire where Mike Myers’ paranoia about women out to get him may or may not be true, based on an article he read in the Weekly World News.

This latest fictionalization of the familiar story, directed by Fabrice Du Welz (Vinyan, Calvaire), takes a strange and unnerving approach that feels like every strange and unnerving approach given to true life stories by cult movie wannabes. Floating somewhere between horror, psychological thriller, satire, and black comedy, Alléluia tries to walk the fine line between serious and hilarious that never fully commits to either.

Former Almodovar muse Lola Dueñas takes on Gloria, the Martha Beck role, portraying her as a supposedly homely woman who refuses to be taken advantage of by Michel, the Ray Fernandez character. Gloria is downtrodden, depressed, and more than a little crazy. The black magic used by Michel worked a little too well, and Gloria is now a psychotically jealous woman who foils their get rich quick schemes because she jumps the gun before Gigolo Michel can actually get paid for his hard work.

The scenario of Michel meeting a woman, getting in close, trying to extract money, and then Gloria killing too early, is repeated three separate times, each repetition headed by the name of Michel’s victim. This repetition has foundations in the real case, as Beck and Fernandez had confessed to 20 murders over the course of two years, but were only convicted of 3. Each repetition in Alléluia just comes back to the same damn well, and feels like you’re seeing 3 sequels to a first story.

Du Welz has no control over his tonality, and his visual work is all over the place. He is far too cautious in his choices, even though the movie is scattershot. At some points, Du Welz thinks it is hilarious, and others he tries for the most somber and dull tones, and, at others, he thinks its a horror flick. This unsure quality gives Alléluia a cautious toe-in-the-water atmosphere, even though the sensitive subject matter demands a self-assured and confident director. At times he pushes the visuals into the real of neo-giallo, but at others it looks like it could be a Haneke film, and at others it has a student film quality to it.

It’s a shame because this is one of those movies that I should have fallen in love with. With a more assured hand, Alléluia could have been a pointed scribe about gender and sexual relations. Or, at least a rollicking good time. Or a frightening one. Or all three at once. Du Welz attempted to go for that last, riskiest, category. Just as the most demanding categories also have the highest points to fall from, Du Welz falls hard, making the greatest of sins: Alléluia is not just a mediocre film, it’s also a boring one.