Dwight and his strong-willed sister Jessie have dedicated their lives to caring for their younger brother Thomas, who suffers from an incurable disease that prevents him from go - ing out in the sunlight. What’s more, Thomas cannot live without regular intakes of human blood. Despite this difficult moral dilemma, Jessie and Dwight can’t leave their brother to die, so they kill hobos and vagabonds they en - counter in the wilderness and take their blood. The constant killing takes its toll on the siblings, and the delicate balance of the close-knit fam - ily begins to unravel when a new neighbour boy wants to befriend Thomas.