Watch Red Line for Free: How to Stream the Movie Online at 123Movies. . Terrified commuters are on the ride of their lives when terrorists send a subway train speeding out of control during rush hour. With the saboteur among them, a group of citizens are now trapped underground and in a race against time if they hope to see daylight again. Full of fast-paced action and suspense, Redline is a thriller that will have you holding on for safety.