Simon is keen to get to work identifying the bones found encased in concrete in the river. Harrow — responsible for putting the bones there in the first place — takes the 'slow and steady' approach to stall him. Then a new case arrives. A woman has been found in a quarry, brutally murdered, a large cavity carved in her chest. Her car is found parked close by; she was a rideshare driver. Police arrest the last passenger, but he claims he's innocent.