In 1653, Cromwell sent Luke Tremayne and his deputy Harry Lloyd to Paris to negotiate secretly with the exiled king Charles II. After a serious mishap to Luke, Harry is forced to complete the mission alone. Luke is nevertheless gainfully employed by a wealthy French aristocrat, the Marquis des Anges, to investigate the murder of his first wife and the attempted murder of his second. Harry assists the English courtiers to solve the murder of two young ladies-in-waiting to the Queen Mother Henriette Marie and together with a Royalist peer is falsely imprisoned and tortured. He escapes and after...

In early 1657, Cromwell, after surviving three assassination attempts, turned to his top investigator, Luke Tremayne, to hunt the would- be killer.

Elements in the army feared that Cromwell would become king and his government fall increasingly into the hands of civilians. Royalist agents played on this fear and planned to take over a strategic military unit to then overthrow the government.

Luke had to uncover the leaders of this plan before they achieved their aim.

Lukes task increased as he had to solve the murders of his initial suspects, who were battered, stabbed, blown apart, or...