Businessman Hector Kirby had ambitious plans for a derelict piece of land along the River Windrush, but the current residents were determined to stop him. So was the person who had hidden something there that was never meant to be discovered. As a rare summer heatwave envelopes Oxfordshire, the local police once again enlist the help of clock repairer Jacob Silver and his wife Sarah in an effort to find who has been stung into action by Kirby's plan.