Betty is spending time with a group of her friends, including a close wealthy friend named Sandra, who is estranged from her husband Harry. Sandra is murdered by her greedy cousin Paul Nugent and he stages it as a botched robbery, all the while framing Harry for it so he can collect Sandra's inheritance. Paul is also putting the moves on Betty, and constantly putting himself in the investigation. When Paul finds out Harry has an alibi he murders her too, only Barnaby is not convinced Harry is guilty. Barnaby investigates deeper to clear Harry and prove Ross is the guilty party before he can kill again.
—charmardee-smith