Warren Black lives in New York City and suffers a recurring nightmare about attending a bullfight that ends in a piercing shrieking noise. The nightmare fills him with doubts about his job as a Brigadier General in the US Air Force who is assigned to nuclear weapons.
Walter Groteschele is a professor with some audacious ideas about nuclear warfare - namely that the common conception that any exchange of nuclear weapons will inevitably and imminently lead to an all-out exchange and the annihilation of the world is wrong. He is a civilian advisor to the Defense Department and Defense Secretary Swenson.
Frank Bogan is commanding general of Strategic Air Command, the nuclear weapons arm of the Air Force, and he possesses faith in the vast array of high-tech equipment at his disposal, enough that he leads a short-notice tour of a visiting Congressman, Hubert Raskob, of SAC headquarters - though he must roust his executive officer, Colonel Warren Cascio, from an unplanned visit with his elderly father, a drunken hillbilly who lives in a basement apartment and whose alcoholism periodically leads to violence.
Jack Grady, a Colonel in the Air Force, leads Group Six, a squadron of Vindicator nuclear bombers, supersonic jet aircraft derived from the B-58 Hustler bombers of the latter 1950s and based near Anchorage, AL. Grady and his wingman Billy Flynn debate the utility of their fellow pilots, young men who seem more like machines than the pilots they flew with in the Second World War.
All of these men are soon caught up when a computer malfunction at SAC headquarters results in replacement of a faulty control piece. The replacement is routine but momentarily freezes up SAC's mainframe as the array of computers reboots. It appears of no concern - except the glitch activates the Fail-Safe box aboard Group Six; at the same time all radios aboard Group Six are jammed by Soviet Russia, and when the fail-safe signal aboard the planes is verified, it leaves Grady and his men thinking that nuclear war has broken out and they must execute their final order - penetrate Soviet Russia from the North Pole and launch multi-megaton explosives onto Moscow.
The President Of The United States now must become involved as he and his translator, Peter Buck, travel deep underground to the White House command bunker, where a "Hot Line" direct voice communicator with the Soviet Premier awaits, with Buck hearing the Russian's voice and translating his words to the President. The President, the Secretary of Defense, and General Bogan work to try and stop Group Six, but the power of the planes and the crews' unshakable working orders - orders that include disregard of all outside voice communication on the suspicion of enemy disinformation - means that the six bombers penetrate Soviet Russia and overcome the Soviet Empire's vast antiaircraft grid.
Making matters worse, when The President innocently asks the Soviet Premier about jamming of Group Six's radios, the Russian initially lies about it, and when he finally tells the truth the President still cannot convince Group Six to disengage. A direct communication link to Soviet air defense headquarters is opened and General Bogan is forced to dragoon one of his technical sergeants into telling the Russians how to detonate nuclear-armed air-to-air missiles, thus blowing up their own planes.
With all indications being that the bombers will reach Moscow, the President makes a deal with the Soviets - a deal so stunning as to shake even the Soviet Premier into realizing that the President's pleas that the attack is an accident are manifestly the truth, but with the sickening realization that the President's proposal is the only way to avoid omnicide.