In Their Sleep (2010)

Sarah and her husband have moved to a house in the country; their son, Loic, a college student, chaffs at the isolation and a tragedy occurs. A year later, Sarah lives alone in the house; distracted by grief, she's sent home from her hospital job at 2 AM. Police on the road warn her of burglaries in the area, then a young man, much like her son, flags her down: he surprised a burglar at his house, and he's being chased. He is Arthur. Sarah gives him a lift, and soon a car is in pursuit. A long night ensues with flashbacks to crimes and chases; can Sarah protect Arthur as she would her own son?