 Neville Grimshaw is found shot on the banks of the river and Morse has another case to solve. Grimshaw was an investigative journalist looking into the business dealings of a major Oxford University benefactor, Andrew Baydon. When opera diva Gladys Probert is shot during an academic procession, witnessed by Morse and Lewis, the police wonder if the bullet was meant for Baydon. Both Probert and Baydon were tyrannical with their staffs and families and they both clearly had enemies. The case becomes more complex when they discover that the victims were shot with two different guns. The resolution of the case revolves around a dark secret involving one of the principals.