The Lake - S1.E1

Arthur Randall's marriage has become a sham (and he is in love with his secretary), but his wife doesn't wish to give him a divorce. It is suggested to him that he and his wife go away for a while in an attempt to work things out. She reluctantly agrees, and they go to their cabin by the lake. While they are boating, Arthur's wife falls overboard and drowns. Before she drowns Arthur pulls a ring from her finger- a ring he intends to give to his secretary. Arthur returns home for a while, but is eventually drawn to return to the scene of his crime.