Detective Inspector Max Arnold lives on a battered houseboat at the end of Cheyne Walk after separating from his art dealer wife Astrid. The son of a local bookshop owner, Max is a far cry from the affluent elite whose crimes he'll help solve along with D.C. Priya Shamsie.

A young woman finds out that her mother worked as a spy for the British Secret Service during World War II and has been on the run ever since.

After saving each other from jumping off a bridge, Henry Bell and Karen Knightly plot to avenge the people who drove them to suicide. Henry will ruin the life of the woman who married Karen's boyfriend, while Karen will work as a secretary for the man who took Henry's job. Whether revenge will be sweet – or bittersweet – is anyone's guess.