0245, 6 December 1941. USS Swordfish spots the Japanese strike force 600 miles from Pearl Harbor. In this alternative history adventure, Japan cancels the attack, preventing U.S. entry into the war. Free from American interference, Hitler's scientists perfect an operational atomic bomb. Demonstrating this newfound power, Germany obliterates a remote British village thus blackmailing Britain into an armistice and forcing America to remain neutral. Undeterred, British Intelligence must ferret out Germany's atomic resources and destroy them. AGATHA, the stunning widow of a downed RAF pilot and superlative field agent in her cover as a neutral Swiss socialite in Berlin, becomes romantically involved with Luftwaffe General Peter von Zimmermann, pilot of the atomic attack, in hopes of gaining actionable intelligence. Discovering the atomic program's location, she leads an assault on the facility, but the Germans still have three operational bombs. Enraged, Hitler orders a strike on Moscow. Zimmermann, despite his confliction over Nazi tyranny, pilots the mission flying a prototype strategic bomber nicknamed "The Linden Tree."