London's Psycho Cyclist by John Broughton

Fortunately, husband-and-wife psychopaths are few and far between. But after a spate of cyclist killings, Vance and Shepherd are called in to investigate an apparently irreprehensible architect and his wife.

When the architect is elected to a high political position, Vance’s suspicions arise. After an ingenious drone device is used to detonate hidden unexploded World War 2 bombs in the area, the duo is certain that the couple have something to do with the crime.

Damian Devenish, the architect, is determined to punish society. Can Vance and Shepherd prevent him from achieving his ultimate, spectacular vendetta?