The film begins with the ex-soldier, Tomaz, unearthing an amulet at an outpost in the woods. It becomes apparent that this is where he was stationed in his former country, which he eventually escaped to make it to London. Tomaz periodically has flashbacks to this time and Mirian, a woman who took shelter with him after he spared her life when he caught her trying to pass the border.In London Tomaz works as a day laborer while sleeping in a derelict building with other refugees. When the building is set on fire, Tomaz is forced to flee suddenly in the night. Unable to breathe from the smoke, he collapses in an alley way and is discovered by Sister Claire, a nun. After visiting him in the hospital she suggests a better way of life for him and takes him to a house, explaining that a woman living there, Magda, needs help with the house upkeep as she cares for her dying mother. As she walks away, she is seen throwing Tomaz's money (which he thought lost) into the sewer.Magda makes it clear she doesn't want Tomaz there and he too is reluctant to stay. However the two grow accustomed to one another and Tomaz tries to perform repairs. When trying to fix the water pipes Tomaz discovers a live bat clogging the toilet. He kills it, but not before it bites him.Tomaz eventually sees Magda's mother, whom she keeps imprisoned in the attic. Though she is extremely ill she attacks Magda in front of Tomaz and he becomes protective of her. He takes her out on the town, fulfilling her wish to go out dancing all night if she was free.Later on, returning home Magda and Tomaz see her mother giving birth to one of the bat like creatures he sees on the toilet. Tomaz goes to consult Sister Claire, and she tells him that the mother is a demon and Magda and her have been charged with keeping it contained for years. Tomaz returns to the house, determined to kill the demon and save Magda. However after stabbing the demon in the throat it bites and attacks Tomaz only to be stopped by Magda.Tomaz then flashes back to his time with Miriam. Developing a crush on her he urges her to stay with him until the end of the war and protects her from fellow soldiers. However after discovering her trying to leave in an attempt to reunite with her daughter, he hunts her down and rapes her.Awakening in the house, Tomaz, determined to protect Magda, returns and attacks the demon. Once he beheads it he realizes that the host body was actually that of the previous occupant of the house, a man who murdered his children. Sister Claire explains that he is now the new host and asks him who he wants to be his guardian. He demands that Magda watch over him. Later, Tomaz is sick. As his stomach begins to move, he too gives birth to one of the creatures.Later, Magda drives up to a convenience store where Miriam is working the counter. After making sure that Miriam is alright she drives off and throws some food in the back where Tomaz is hiding under a blanket. (Copied from Wikipedia)