The reason for this success is never clearly explained, but a major factor appears to have been the transfer of the French navy to the Germans after the fall of France.

A former schoolteacher, his ability to speak German had secured his release to work as a translator for the military governor of region, Generalleutnant Kurt von Glass.

Though Glass supports Penny's suggestions for fostering Anglo-German amity, the region's security chief, Standartenführer Stolz, is using every pretext for brutalising the local population.

Penny and Locke nearly miss curfew, but are saved at the last minute by the timely arrival of Matty Cordington, their old friend, who was released from internment and who brought Sara Burskin, a Polish refugee, with him.

Once again involved with the resistance, Penny assists in a number of their operations, informing Kennedy of an attempt by the IRA to assassinate Glass and helping to smuggle a Danish scientist and his wife out of the country.

Glass himself soon leaves Britain to serve on the Eastern Front; his departure coincides with the roundup of foreign-born Jews by the authorities, including one in hiding on Cordington's estate.

Penny is therefore surprised when Kennedy suddenly contacts him in July with a new mission: to smuggle out Otto Frisch, who the Gestapo has discovered knows information which could be vital to the development of a "superbomb".

Frisch is captured along with the Jenners, and Penny and Cordington travel to Imber in order to stage an escape from the concentration camp the Germans have built there.

Penny arrives in time to save Cordington but not to stop the ambush, which leads the Germans and their British auxiliaries to massacre everyone in the nearby town of Merricombe in response.

Killing Sara, Penny and Kennedy race to London to prevent Cordington from revealing the location of the resistance meeting to the Germans.

Pursued by the authorities, they make it to London and warn the resistance, but they are unable to stop Cordington before he executes his real plan: using the credentials given to him by the Gestapo to get through security at the coronation and setting off a suicide bomb that kills the Regent and assembled German leadership.

Nick Penny - The main character, he was the German master of the local grammar school prior to becoming a sergeant in the Intelligence Corps during the war.

Generalleutnant Kurt von Glass - Provincial governor of the Westgau, the German-established province (gau) encompassing the West Country.

Margaret Penny - Nick's mother, who appears increasingly withdrawn from reality as a consequence of the losses she has suffered from the German invasion.

Hubert Leech - A newsagent who profits from the war and occupation, taking advantage of Nazi persecutions of Jewish businesses to purchase the Jenners' tea room.