Season 4, Episode 6:
When Brian Lane's dog Scampi digs up a body during his routine walk on the common, the team finds itself in a very unusual situation, even before the investigation has begun. Janice Small, the widow of a notorious criminal, confesses to killing her husband's lover as soon as she hears news of the discovery of the corpse. However, further investigation reveals that the skeleton is 600 years old. Does the grounds of the common hide the grim remains of more than one victim?