An act of desperation spirals dramatically out of control in French writer/director Erick Zonca's twisting but overlong English-language debut. Tilda Swinton is fearlessly untamed as Julia - a manipulative, bed-hopping alcoholic whose unprincipled behaviour reaches a violent low when she is persuaded to kidnap a young boy (Aidan Gould) to extort money from his rich grandfather. John Cassavetes-style realism then unexpectedly mutates into an overblown action thriller as the duo wind up in Mexico and Julia's plans crumble spectacularly. Though Julia really is a loathsome creature, Swinton infuses her with a ferocious energy that's riveting to watch and often acerbically humorous. Even where her maltreatment of the boy feels uncomfortably exploitative, the integrity of the performance dominates. Zonca strives to maintain this air of dark truth, offering no apologies for his characters' conduct. Yet by taking an overall amoral approach, he makes his contrived and redemptive finale seem inappropriately dishonest.

An alcoholic becomes involved in a fellow A.A. member's plan to kidnap her young son from the boy's wealthy grandfather.