Dr. Steven Murphy is a renowned cardiovascular surgeon who presides over a spotless household with his wife and two children. Lurking at the margins of his idyllic suburban existence is Martin, a fatherless teen who insinuates himself into the doctor's life in gradually unsettling ways. Steven, a charismatic surgeon, is forced to make an unthinkable sacrifice after his life starts to fall apart, when the behavior of a teenage boy he has taken under his wing turns sinister.