To Pay the Ferryman

A cold case in the city of the dead.
D.I. Lomond is a devoted family man. A good detective.
When the body of a young woman involved in the worlds of art and adult streaming is found in the River Clyde, Lomond believes there may be echoes of a cold case from the start of his career: an unsolved death on a rural Scottish estate in the 1990s.
Then, a Swedish feminist activist, who also has a connection to Lomond's past, arrives in the city to protest against the failure of the police to find the killer.
The victims all seem to be drawn from the world of art and business. Is the cold case the answer, or just part of the key, and could the killer be about to get dangerously close to Lomond and his family?