It is early 1945 and Nazi Germany, reeling under the relentless onslaught of the Allied armies, looks to futuristic superweapons like jet fighters, V-1 buzz bombs, and V-2 rockets for its salvation. But Peter Miller, an analyst at the headquarters of the Office of Strategic Services in Washington D.C., learns of a secret Nazi weapons project that may pose a far greater threat: the Black Gate. Sent alone on a perilous mission into the heart of Germany in the guise of an SS officer, Peter discovers that Nazi scientists have recreated an ancient machine that opens a portal to another universe, a gate they believe literally leads to Hell. With the help of Mina Hass, a beautiful woman who is also the lover and confidant of the madman leading the project, Peter must find a way to close the gate forever before the Nazis unwittingly unleash Armageddon...