Little Sister - Is she witness, victim or killer? A nail-biting thriller with twists you'll never see coming

Detective Jonah Sheens is enjoying a moment of peace and quiet, when a teenage girl wanders out of the woods.
She's striking, with flame-red hair and a pale complexion.
She's also covered in blood.

Jonah races to her, eager to help. She insists she's fine. It's her sister he needs to worry about.
Jonah quickly discovers that Keely and her sister, Nina, disappeared from a children's home a week ago. Now, Keely is here - but Nina's still missing.
Keely likes to play games. She knows where her sister is - but before she tells, she wants Jonah's full attention.
Is she killer, witness, or victim? And will Jonah find out what Keely's hiding, in time to save Nina?