On the face of it, "Mona" (Natalie Press) is a bit of a tomboy with few friends and an untrusting nature. When she meets the rather more entitled "Tamsin" (Emily Blunt) you'd expect sparks to fly, but gradually the pair realise that they have more in common than they'd initially thought with their opposites definitely starting to attract. The only real fly in their increasingly idyllic ointment is brother "Phil" (Paddy Considine). He is a reformed criminal who has turned to religiosity with an almost violent zealousness - and he is determined to indoctrinate "Mona" whether she likes it or not....