Those vampires really are not prepared to get their fangs out of our necks. Last week Jim Jarmusch premiered Only Lovers Left Alive, his own hip take on the blood-sucker genre, at the Cannes Film Festival. Now Neil Jordan, who directed Interview with a Vampire nearly two decades ago, gets back on board with this strange, murky, often unsettling adaptation of a Moira Buffini play.

Gemma Arterton (all brass and stockings) and Saoirse Ronan (perfectly wasted) play vampires, apparently mother and daughter, who, after decades of rambling, find themselves holed up in a crumbling seaside town. The perennially cowed Daniel Mays, a weak-willed hotelier, allows them to set up a brothel in his establishment.

Soon the authorities are taking an interest. But there are more worrying problems. The patriarchal cadre to which the heroines once belonged is intent on tracking them down and making these undead a little more, well, dead.

Byzantium abounds with classic Jordan flourishes. More at home to red than any director since Michael Powell, he revels in the image of a remote island bathing itself in torrents of blood. For the 126th time in his career, he makes something seedily compelling of a wasted beach resort. The feminist subtext adds weight to a fantastic confection.

Unfortunately, the story never sorts out its various strands. The film is not short, but there's still too much going: a romance with a sick boy; interactions with teachers; Mays's sad life. The vampires' back-story (a 19th-century pocket gothic romp) makes unfair demands of Jonny Lee Miller. Too fond of his cackling, too layered in bad make-up, Miller seems to have found himself in an Italian horror flick of the 1970s.

Maybe that was Jordan's intention. Maybe not. Byzantium never quite decides if it's playing it straight or giving in to camp. The result is a slightly frustrating picture: full of brilliant things, but hampered with at least three split personalities.

A worthwhile addition to groaning genre, nonetheless.