When a car swerves into a telephone pole, a young girl rushes to help the injured driver; but when the driver takes her hostage as police arrive, she must find a way to escape her captor.

You really pulled me into the world and gave a good idea of how the story will take shape, to have her be captured is a twist that surprises me and makes me want to watch the final film/read the screenplay.
Only thing I’d say is to clean up the syntax; specifically the third “when” makes it feel a bit clunky to read. Maybe, “but when the driver takes her hostage before the police arrive, she must find a way to escape her captor.”
Overall, really great job.