A ride for Sara

Who is the killer? And why did they choose Sara as their target?

Law student Sara has to work two jobs alongside her studies to pay the bills. And sometimes she has to do things most people wouldn't expect of her.
A busy evening shift at the bar is drawing to a close when her boss orders her to take care of a drunk customer in the toilet. So, she helps her outside for some fresh air, where they call for a ride home, give their addresses and a moment later they are each sitting in the back of a car, heading into the night.

Tired, Sara falls asleep on the way, and when she wakes up, she finds herself in a wealthy neighbourhood on the other side of town and realises that she and the other girl, also named Sara, have swapped cars. With no money, she has no choice but to walk home. But outside her house, police lights are flashing, and there's a dead body on the pavement – Sara's.

Was she the killer's real target? Or did she just get into the wrong car? And why would someone want one of them dead?