Tyrannosaur movie story revolves around Peter Mullan. He is a underemployed widower who is adicted to alcohol, disturb by violence and a rage that is driving him to selfslaughter, later his life undergoes a change after he kills his dog in a extreme anger .
Olivia Colman is an Christian woman, who works in charity shop, takes pity on Peter Mullan. Further circumstance brings the pair together, Olivia Colman appears as Peter Mullan's guardian angel. Olivia Colman has a dark secret of her own which compress Joseph to venture back into his former life.