Set during the Cold War, the novel opens with a Strategic Air Command (SAC) B-52 bomber crew competing in SAC's annual Bombing and Navigation Competition over Wyoming. Captain Patrick McLanahan, the radar navigator and a casual, instinct-driven Californian, and First Lieutenant David Luger, his meticulous Texan navigator partner, guide their aging bomber through a demanding low-altitude bomb run. When the Doppler navigation system fails, McLanahan switches to manual bombing and drops with near-perfect accuracy through sheer intuition. The crew sweeps nearly every trophy, catching the attention of Lieutenant-General Bradley Elliott.
Two thousand miles west, a far more serious crisis unfolds. Near Kavaznya, a secret research complex on the Soviet Union's Kamchatka peninsula, a laser weapon powered by a massive nuclear reactor destroys a US surveillance satellite and vaporizes an American RC-135 reconnaissance aircraft and its 12-person crew. In the White House Situation Room, General Wilbur Curtis, Chairman of the Joint Chiefs of Staff, suspects an operational Soviet laser defense system, but Central Intelligence Agency (CIA) Director Kenneth Mitchell dismisses the theory. The President authorizes Curtis to develop a secret military response. At the United Nations (UN) Security Council, the American delegation fails to present evidence and is embarrassed when Soviet Ambassador Dmitri Karmarov denies involvement.
Elliott commands Dreamland, a highly classified research facility in the Nevada desert, where he has overseen the transformation of a standard B-52 into the "Old Dog," a heavily modified bomber nicknamed the Megafortress. The aircraft features radar-absorbing fibersteel skin, Scorpion air-to-air missiles, HARM anti-radar missiles, Stinger airmine rockets, AGM-130 Striker glide bombs, satellite navigation, and an automatic terrain-avoidance system. When Curtis visits Dreamland, Elliott suggests the Old Dog could strike Kavaznya. Meanwhile, Secretary of State Marshall Brent warns Karmarov that the Pentagon is considering deploying Ice Fortress, a classified armed American space platform. Karmarov's agitated reaction confirms suspicions about the laser.
At Ford Air Force Base in California, McLanahan faces a crossroads between a coveted headquarters assignment, family obligations to his widowed mother, and his girlfriend Catherine McGraith's desire that he leave the service. Before he can decide, he receives mysterious orders for a classified exercise and is covertly transported to Dreamland, where Elliott recruits him as the Old Dog's radar navigator. The crew assembles under Colonel James Anderson, the project's demanding chief pilot, alongside Lieutenant Colonel John Ormack as copilot, Dr. Wendy Tork as electronic warfare operator, Dr. Lewis Campos as gunner, and Dr. Angelina Pereira as Campos's assistant. McLanahan proves the bomber's advanced computers are vulnerable to failure, demonstrating the need for a second navigator.
At the UN, Karmarov enters a plea of nolo contendere (no contest), acknowledging that activity at Kavaznya "may have caused a situation" affecting the RC-135, and the Old Dog project is ordered to stand down. The calm shatters, however, when the Kavaznya laser destroys a Javelin, a small mobile intercontinental ballistic missile (ICBM), after it reaches 400 nautical miles altitude during a test launch. The USS Lawrence, a disguised intelligence vessel monitoring Kavaznya offshore, detects signals suggesting the radar is sending steering data to an unknown second party. Curtis later presents photographic evidence confirming that a large mirror attached to the Soviet Salyut 19 space station redirects the laser beam to distant targets.
Brent demands the Soviets disarm the mirror within three days at the UN Security Council. When they refuse, Curtis persuades the President to deploy Ice Fortress, an armed platform carrying X-ray laser satellites, each powered by a nuclear warhead. During assembly from the Space Shuttle Atlantis, the Kavaznya laser fires at the station, detonating one of the satellites and killing Navy Commander Richard Seedeck. The President then authorizes two B-1B Excalibur bombers armed with Striker glide bombs to strike Kavaznya directly.
At Dreamland, Elliott reconvenes the Old Dog crew, but armed attackers assault the facility with mortar fire and automatic weapons. Anderson and Campos are killed. Elliott, wounded in the right leg, orders an emergency departure. McLanahan fires a Scorpion missile to clear the runway, and the Old Dog launches carrying six crew: Elliott, Ormack, McLanahan, Luger (who has joined as second navigator), Wendy, and Angelina. Over the Arctic Ocean, the B-1s are intercepted by Soviet fighters and neutralized. Curtis convinces the President that the Old Dog is the only remaining option and secures strike authorization without recall options, fearing a security leak.
Elliott stages a fake emergency, making the Old Dog appear to crash into the Pacific, then proceeds at low altitude toward Russia. After coercing the commander at Shemya Air Force Base in the Aleutians into providing emergency refueling, the crew bluffs past Soviet air traffic controllers using a stolen call sign and exploits a radar coverage gap to reach the Kamchatka peninsula. The Old Dog battles through intense air defenses, with Wendy firing HARM missiles at radar sites while Luger navigates through the mountains. Soviet MiG-25 interceptors attack, and though the crew destroys several, the bomber sustains devastating damage to its tail, engines, wingtip, and fuel tanks.
Approaching Kavaznya, McLanahan launches Quail decoy drones that draw the laser's targeting radar away from the bomber. The laser vaporizes one decoy, creating a vacuum blast that nearly crashes the Old Dog. McLanahan launches the Striker glide bomb, initially aimed at a power substation, then redirects it toward the mirror-housing dome after spotting it on the infrared display. After a tense delay, the bomb detonates, destroying the mirror building and knocking out power to the complex.
During the escape, Soviet pilot Yuri Papendreyov pursues the Old Dog in a MiG-29 Fulcrum, a Soviet fighter jet, firing an AA-8 heat-seeking missile that hits the fuselage. Luger sustains severe injuries when his instrument console explodes. Papendreyov later takes a freshly armed Fulcrum from Ossora Airfield and continues his unauthorized pursuit. With fuel critically low and Elliott barely conscious from blood loss, the crew votes to land at Anadyr, a closed Soviet airbase McLanahan spots on his chart. Elliott manages to set the bomber down on the snow-covered runway.
The crew commandeers a fuel truck from the base's lone caretaker. When a local militia vehicle arrives, Luger, despite his severe injuries, drags himself from the bomber and rams the fuel truck into it, sacrificing his life to save the crew. McLanahan, who has never performed a takeoff, takes the pilot's seat and launches the Old Dog on six engines following Ormack's verbal instructions, as both Elliott and Ormack are incapacitated by wounds.
Papendreyov arrives as the Old Dog lifts off and fires his last missiles, but McLanahan's steep climb causes them to lose their lock. After a series of desperate maneuvers, McLanahan orders Angelina to fire the last Scorpion missile, which locks onto the MiG's afterburner exhaust and destroys it. The Old Dog turns east toward the Bering Strait.
The surviving crew recovers at an Air National Guard infirmary in Nome, Alaska. Elliott, who has lost his right leg, reports that the Soviets have agreed not to rebuild Kavaznya while the US will not launch another Ice Fortress. The security leak is traced to an aide in CIA Director Mitchell's office who had been passing information to the Soviets, explaining the attacks on Dreamland and the interception of the B-1s. McLanahan accepts a position at Dreamland and asks Wendy to join him, which she agrees to.