Far from a biography, the film uses the real-life story as the launching pad for an surreal, surprisingly touching dramedy anchored by a mesmerising dual turn from Kate and Rooney Mara. We begin in a Dublin courtroom, where Jean and Joan are called to the witness stand as their neighbour and shared love interest, Mr Mulroney (Orlando Bloom), seeks to file a restraining order against them. Sporting a thick Irish accent, Bloom has plenty of fun as a rakish married man who thoroughly enjoyed a brief affair with the sisters (he unsubtly refers to them as his “cowgirls”), but while he tells the jury the relationship was “only sexual”, the Holbrookes — often giddy and smiling —  declare he is “the love of our lives”. When they must answer for their various modes of harassing Mulroney, several counts of arson included, they ask the court, speaking in two as always, “Is it a crime to love?”

Taking a somewhat episodic approach, the film moves from scene to scene with a dreamlike sense of pace, as the sisters find an unlikely friend in a benevolent landlord (John Kavanagh) and try to work on their crippling co-dependency — the pair can’t clean the house without holding the vacuum at the same time — with the help of an attentive social worker (Domhnall Gleeson).