In July 1939, British hunter Thorndike, vacationing in Bavaria, has Hitler in his gun sight. He is captured, beaten, left for dead, and escapes back to London where he is hounded by German agents and aided by a young woman.
In July 1939, English big-game hunter Captain Alan Thorndike infiltrates Adolph Hitler's retreat Berchtesgaden in the Bavarian Alps and takes aim at Hitler with his high-powered rifle. Although Thorndike had intended to carry out a "sporting stalk" only, and does not have bullets in his gun, he loads the weapon after locating the target. A German soldier surprises him, however, and his bullet goes astray. Thorndike is brought to Gestapo Major Quive-Smith, to whom he explains that he did not intend to kill Hitler. Quive-Smith does not believe him, however, and orders him to confess that his assassination attempt was at the request of the British government. Although Quive-Smith promises him freedom, Thorndike refuses to sign the prepared confession and is tortured by the Gestapo. When Thorndike still refuses to sign, Quive-Smith arranges for him to be thrown off a cliff in what will look like an accident, but he falls into a river and survives. The next day, the Gestapo searches for Thorndike but he eludes his pursuers and reaches a harbor, where he boards a boat bound for Britain. An intrepid cabin boy named Vaner hides him while one of Quive-Smith's men, Mr. Jones, boards with Thorndike's passport. Vaner keeps Thorndike hidden during the journey, but once he is ashore, Thorndike realizes that Jones and other Gestapo agents are following him, and he ducks into an apartment to escape. He appeals to the apartment's resident, a young Cockney woman named Jerry Stokes, for aid, and she helps him get to his brother's house. Thorndike's brother, Lord Gerald Risborough, is an ambassador, who warns him that the German embassy is looking for him, and that England must acquiesce if Germany demands his extradition. Thorndike vows to disappear from England, then leaves with Jerry and sleeps on her couch. The next morning, Thorndike outlines his plans and does not notice that Jerry has fallen in love with him. She pouts until he takes her to buy a pin to replace the one she lost from her tam-o'-shanter, and she chooses a large chromium arrow. Jerry then accompanies Thorndike to the office of his solicitor, Saul Farnsworthy, where he tries to give her five hundred pounds. She refuses the money, and their squabbling is cut short when an assistant announces that Quive-Smith and Jones are on their way to the office. Thorndike and Jerry escape to the Underground, where Thorndike is chased by Jones. After a fight, Jones is electrocuted on the third rail, and, because he still carries Thorndike's passport, his corpse is identified as the hunter. Realizing that the British police are now after him as well, Thorndike instructs Jerry to write to him at Lyme Regis in three weeks with any news. After a tearful farewell, Jerry returns to her apartment, where Quive-Smith is waiting for her. Three weeks later, Thorndike, who has been living in a cave in the woods, goes to the post office to pick up Jerry's letter. When he returns to his cave, Thorndike discovers that the letter is from Quive-Smith, who has followed him and blocked the cave's opening. Through a small opening, Quive-Smith hands Thorndike Jerry's tam-o'-shanter and says that she was found dead on the street after jumping out her window. Enraged by Jerry's murder, Thorndike finally admits that he did intend to kill Hitler, although he did not realize it at the time. Stalling for time, Thorndike agrees to sign the confession and constructs a bow while Quive-Smith opens the entrance to the cave. As Quive-Smith reaches for the signed confession, Thorndike shoots him with the arrow from Jerry's hat. As he dies, Quive-Smith shoots Thorndike with a pistol, but before he collapses, Thorndike destroys the confession. Months pass as Thorndike recuperates and Europe is thrown into war. Once he has recovered, Thorndike joins the RAF, and on a reconnaissance mission over Germany, bails out with a high-powered rifle, intent on fulfilling his purpose this time.
On July 29, 1939, renowned British big game hunter Captain Alan Thorndike (Walter Pidgeon) slips through the forest undetected near the Berghof, Adolf Hitler's residence near Berchtesgaden. Getting the dictator in his telescopic sight, he pulls the trigger on his unloaded rifle and gives a wave. He ponders a moment, then loads a live round, but is discovered at the last second by a guard, and the shot goes wild.
After being beaten up, Thorndike is taken to Major Quive-Smith (George Sanders). Quive-Smith is also a devoted hunter and an admirer of Thorndike. Thorndike explains that it was a "sporting stalk", not to kill, but just for the thrill of going after the biggest game of all. The Nazi half-believes him, but insists he sign a confession that he was in fact working for His Majesty's government. When Thorndike refuses, he is tortured, but remains steadfast and warns of "questions being asked in high places" if he is killed, as his brother, Lord Risborough (Frederick Worlock), is a very important diplomat. The phrase gives Quive-Smith the idea to have Thorndike thrown off a cliff to make his death look like an accident.
Thorndike survives when his knapsack gets caught in a tree, breaking his fall. He eludes his German pursuers and reaches a port. He steals a rowboat, but is forced to abandon it hastily when a patrol boat comes near. He swims to a Danish ship about to sail for London. Vaner (Roddy McDowall), the English cabin boy, helps Thorndike hide. The Germans find Thorndike's coat and passport aboard the rowboat and search the nearby ship. Though they find nothing, they place agent Mr. Jones (John Carradine) on board using Thorndike's passport to continue looking even after the ship leaves the harbor.
Jones is met by German agents in London. Thorndike, mistakenly believing he is now safe, casually debarks and is spotted. He manages to shake off his pursuers by ducking into the apartment of Jerry Stokes (Joan Bennett), a young woman. Jerry lends him money so he can reach his brother.
When Lord Risborough tells his brother that the British government, continuing its pre-war policy of appeasement, would have to extradite him if he were found, Thorndike decides to hide in Africa. Jerry tries to refuse a large cash reward, leading Lady Risborough (Heather Thatcher) to assume that it is payment for other services, but Thorndike insists. He also buys her a new hatpin, as she had lost hers when they first met. She chooses a cheap chromium arrow and insists Thorndike present it to her. Thorndike likens it to her, saying both are "straight and shiny". By this point, Jerry is in love.
Quive-Smith arrives in London to join the hunt. When Thorndike calls on his solicitor, Saul Farnsworthy (Holmes Herbert), the Nazis are once again on his trail. Chased into a London Underground station, Thorndike struggles with Jones, who is killed when he is thrown onto an electrified rail.
Thorndike tells Jerry to have Lord Risborough send him a letter in three weeks time care of Lyme Regis Post Office. Thorndike hides in a cave. However, when he goes to pick up the letter, the postmistress (Eily Malyon) seems alarmed and sends a girl on an errand. Thorndike grabs the letter and beats a hasty retreat. Back at his cave, he finds the letter is from Quive-Smith, who has followed him to his lair.
Quive-Smith seals the only entrance and passes his quarry the confession and a pen through an air hole, threatening to leave him trapped inside. Quive-Smith also slides in Jerry's beret with the arrow pin, informing Thorndike that his men murdered Jerry by throwing her out a window to her death when she would not betray him. They only discovered Thorndike's location through the address he had written down for her. Badgered by the Nazi, the grief-stricken Thorndike finally admits that he subconsciously intended to assassinate Hitler after all. He then agrees to sign the confession. Quive-Smith unblocks the entrance, but waits to shoot him as he crawls out. Thorndike however has other plans; he uses his belt, a slat from his bed, and a stick to fabricate a bow, using Jerry's pin as the tip of a makeshift arrow, and shoots the German through the air hole. When Thorndike emerges, Quive-Smith manages to wound him before dying. By the time Thorndike recovers, the war has started (September 1, 1939).
Over one year later, Thorndike joins the R.A.F. as a Bomber Command crewman. On a mission over Germany, Thorndike unexpectedly parachutes into the Reich with his hunting rifle to finish what he had started: to find and kill Hitler.
