Bock Kills Her Father, written by Adam J.A. Cass and directed by Penny Harpham is a tense, ominous and beautifully performed piece of theatre let down only by a slightly muddled second half and a too-abrupt ending. Stephanie Bock, a somewhat reserved young woman, arrives in a new town looking for her father. Her intentions would be mysterious if the title didn’t spoil them for us, but this is a play more about the why than the what of her actions. Bock falls in with a band of wild and potentially dangerous girls, but it soon becomes clear that they may know more about her father than they’re letting on.

It’s not so much that none of the characters are what they seem, it’s that there is a certain ambiguity to each of them; even the ones who are more or less as they initially present themselves could be hiding something. From the opening minutes, Bock could be as unhinged as the others or just a confused girl trying to figure out who her father is and what impact he’s had on her life. Or maybe she’s both. Emma Annand gives a brilliant performance as Bock, making her simultaneously sympathetic and fascinating. The character is constantly flirting with falling deeper into the twisted web of the other girls, and Annand walks a fine tightrope in making us never entirely sure which way she’ll fall.

The script turns the nature of the characters themselves into a constant source of tension. This is especially true of Marissa O’Reilly, who makes Taylor downright terrifying to watch. Ruby Hughes and Annie Lumsden maintain a strong uncertainty to the complicity or innocence of their characters in the events unfolding while Emina Ashman rounds out the cast as the, by turns, funny, tragic and unsettling D’Agostino. The script asks a lot of the cast and each one of them rises to the challenge of veering between conflicted, sinister and animalistic.

The aggressive interactions of the characters and the particular cadence of the dialogue is somewhat reminiscent of Nick Enright’s Blackrock, which examined toxic male friendships and misogyny against the backdrop of a working class town. Bock Kills Her Father very nearly does the same thing with female characters, but the concerns here are different. These characters may be dangerous to each other, themselves and everyone around them but ultimately their connection is the safest thing in their world, for better or worse.

The first half of the play moves things into place, introducing the characters and slowly revealing Bock’s intentions. The more we learn about these women the more portentous everything we see feels. But this is part of the play’s biggest flaw; Bock Kills Her Father feels very much like its setting up for twists that never really come. The individual connections of the other girls to Bock’s father are treated like shocking reveals, but seem obvious and telegraphed early on. Knowing that the cast is entirely female going in means that we also know we’ll never actually see Bock’s father, creating a curiosity as to how this is all going to end. While the absence of this key character does play into the resolution, it ultimately means that the ending feels a little abrupt and unsatisfying. Additionally, the play never really does enough work to explain Bock’s motivations in a way that make them credible, despite the best efforts of the cast. As such the denouement struggles to lend gravitas to a slightly flimsy central concept, robbing it of the sort of satisfaction you’d hope for from such an otherwise strong play.

Nonetheless, Bock Kills Her Father is gripping and compelling theatre compounded by daring performances, a fittingly sparse set, haunting sound design and atmospheric lighting. From the opening scene is it riveting and disturbing, building as it goes to moments of black humour, terror and surprising tenderness. It’s edge-of-your-seat stuff.