A killer released on parole and local legend make for an interesting tale in Lynne Davison’s feature debut.

Cathy (Deirdre Mullins) is a probation officer in a small Irish village who volunteers to take on ‘Bloody’ Mary Laidlaw (Derbhle Crotty), just released from prison after serving twenty years for murder. The locals are convinced she’s a witch, and she certainly doesn’t do anything to dispel the stories. When two children go missing, suspicions and emotions run high but the truth is more sinister than anyone could imagine.

Blending elements of folk horror, Matt Harvey’s script takes a premise that could form the basis of an ITV crime serial and turns it into a mix of pure evil and mounting terror. As Mary, Derbhle Crotty is brilliantly nasty, providing a solid backbone for the malevolence of the story. There’s a risk when a film shows too much ‘behind the curtain’ of the plot too early, which is what happens at around the halfway point here, but Mandrake still has a number of surprises up its grimy sleeve.

Deirdre Mullins is equally good as the conflicted Cathy, hoping for the good in people even when there’s no trace. She appears to be an outsider in the community even though her ex-husband (played by Paul Kennedy) is a local police officer. Her child (Jude Hill) is being brought up by another woman, something Mary exploits when getting under the skin of Cathy.

With a deft blending of styles, Davison has crafted a moody and often bleak nightmare of a film that lingers in the mind long after the credits roll.