Murder Call Season 2 Episode 17 Booming Business

Brian Hart is on a train met by a woman he obviously knows. An argument follows. She leaves as his wife calls him on the mobile phone. Moments later Brian Hart is killed when a letter bomb concealed in a card explodes. Was Brian Hart having an affair? Had his wife found out about? Nothing is what it seems as Steve and Tessa begin to uncover the web of intrigue surrounding this horrific death.