The first manned spacecraft, fired from an English launchpad, is first lost from radar, then roars back to Earth and crashes in a farmer's field, and is found to contain only one of the three men who took off in it; and he is unable to talk but appears to be undergoing a torturous physical and mental metamorphosis.

In the early days of World War II, a German U-boat is sunk in Canada's Hudson Bay. Hoping to evade capture, a small band of German soldiers led by commanding officer Lieutenant Hirth attempts to cross the border into the United States, which has not yet entered the war and is officially neutral. Along the way, the German soldiers encounter brave men such as a French-Canadian fur trapper, Johnnie, a leader of a Hutterite farming community, Peter, an author, Philip and a soldier, Andy Brock.