Streetwise Sybil Foster finds herself accused of murder after escaping from a mental institution where she was being held. The struggle to avoid capture begins to threaten her own sanity. Meanwhile, DS Duvall's investigation begins to gather momentum as the hunt for Sybil gets underway.

With another man dead, the evidence begins to mount against Sybil, sending her mind into overdrive - to the point where she begins to question her own innocence. But when she strikes a chord with the compassionate DS Duvall, he begins to realise that there is more to her than meets the eye.