There is only one Blenheim flying today, rebuilt from parts, and based at the Imperial War Museum in Duxford, England. A Canadian version of the Blenheim known as the Bolingbroke is currently being restored to “ground-running condition” at the Canadian Warplane Heritage Museum in Hamilton, Ontario, and a few other examples survive in static museum exhibits. I spent a day checking out the Blenheim on permanent display in the RAF Museum at Hendon, London, where the docent was kind enough to remove the front cockpit escape hatch so I could stick my head up into the nose of the plane (as Jamie does when he’s inspecting 648 Squadron’s aircraft in the rain) and try to imagine what it might be like to fly in it. Standing next to this Blenheim’s wing, with my head level with the rear gunner’s turret, I found my heart aching at how small the plane is. It is much smaller than other twin-engined bombers. It is two feet shorter than a Spitfire fighter plane and only a foot taller than a Messerschmitt 109 fighter. Its crew of three must have been tightly packed. And as one Blenheim pilot put it, if you met German fighter aircraft while you were flying, you didn’t come home.

But the RAF continued to use these planes well into the war, in Africa and the Far East as well as at home. As the war progressed, the armor and armament improved, and the Blenheims were often equipped with early and experimental radar. Jamie’s fictional 648 Squadron is most closely based on the real 248 Squadron, who also flew out of Scotland over the North Sea in the winter of 1940–1941. In real life, 248 Squadron did indeed pick up foreign language radio transmissions which they believed to be German.

The idea of overhearing German radio transmissions leads me to “Odysseus” and his mission. Felix Baer’s landings in Scotland were inspired by two unrelated wartime incidents: the flight of Rudolf Hess made on 10–11 May 1941, and the interception of a German bomber whose crew defected to the United Kingdom on 9 May 1943. Rudolf Hess was, believe it or not, Hitler’s Deputy Führer when he flew to Scotland in a Messerschmitt 110 Luftwaffe night-fighter fitted with long-range fuel tanks. Hess had consulted the aircraft designer himself, Willy Messerschmitt, about modifications and training on the aircraft to enable him to make the flight. To this day, no one is really sure what Hess hoped to achieve. Theories are that he might have had key information to deliver about Germany’s imminent invasion of the Soviet Union in June 1941; or he may have been invited by British Intelligence; or he may have acted as an emissary on behalf of someone else.