Night Mary (2008)

Meet Mary Specter, a misunderstood teenage girl trained to be a lucid dreamer. Mary's father runs a sleep disorder clinic where Mary enters the ghastly dreams of severely disturbed people in an attempt to help them. When a patient is revealed to be a serial killer, the nightmare world and the waking one become intertwined, putting Mary in real jeopardy. Set in a world where the boundaries between dreams and reality are tenuous, Night Mary, courtesy of Rick Remender and Kieron Dwyer (Remains), is a very dark and terrifying trip into psychological horror.