The Chequered Box

S4 E5: Adrian Fell, a highly respected and sharp-witted police officer, is connected to the death of a barrister when a reporter witnesses the officer at the scene of the crime, seemingly staring at the body and stealing evidence. It is then up to Jonathan to find out if he is, in fact, a ruthless killer, and what sinister secret is contained within Fell's strange chequered box.