When a young woman is fatally mowed down by an out-of-control car, it's thought to be a tragic accident — the driver having apparently died behind the wheel. But as evidence suggest the driver was dead hours before the accident, Allie and Duncan find themselves investigating a mysterious double homicide. As the mystery deepens tensions rise between our own detectives. Even Duncan is starting to question Matt's leadership style. Rhys questions Allie's intense and almost punishing martial arts obsession and uncovers a secret from her past. (thetvdb.com)