"These chaps have stolen a cannonball and don't have the cannon to fire it" the Special Adviser on Nuclear Security told the Prime Minister after the most sensational aircraft hijacking since the attacks on the Twin Towers in New York and the Pentagon in Washington on September 11, 2001.
A veteran freelance pilot and his charter plane, Tango George, hired to carry Nigerian Muslim pilgrims to Saudi Arabia, was taken over by the Palestinian co-pilot in the name of a previously unknown Palestinian liberation organisation. Forced at pistol point to divert to Faro airport in the Algarve, Portugal, the lone hijacker is joined by a well-armed Arab gang and its leader takes over command of the plane. Tango-George secures fuel and provisions in exchange for all but ten Nigerian hostages, and flies on to Carlisle airport after demanding that the pilot's one-time lover, now married and living in the area, be brought to the airport, a ruse for the aircraft to rendezvous with other members of the gang who have stolen plutonium from the British nuclear weapons establishment at Windscale.
The plutonium is loaded aboard Tango-George as British security forces close in, but the hijacked aircraft takes off from Carlisle after a brief fire-fight with security forces, whose actions have been hampered by the prime minister's fears of disaster. The PM ignores the advice that the plutonium is a mere cannonball and can't be made lethal without special technical equipment. The world holds its breath as Tango George meanders through the skies above Europe and the Middle East. Life in major cities is brought to standstill as organisations trained for a terrorist disaster are mobilised, first in the Carlisle area, then in Birmingham and London. Tango George flies low over them, circling Buckingham Palace and flying on to circle Nato headquarters in Brussels. As Tango George flies on eastwards, Russian nuclear forces are poised to react to what they believe may be a nuclear attack from the west in frightening hours before the aircraft changes course, flying across Switzerland and down the western coast of Italy. As Tango-George heads towards Israel, military chiefs there, concerned that what appears to be a flying nuclear bomb is intended for them, send aircraft and naval craft to intercept it. By this time, Nato is also planning to shoot the hijacked plane down over sea or desert. Another change of course takes Tango George south over the Nile Delta, narrowly missing being shot down by Egypt's automatic air defences around the Aswan dam, and continues south down the Red Sea.
Nato and Israeli military chiefs assume that Tango George's cargo is destined for Arab terrorists known to have bases in the southern part of Yemen. French jet-fighters take off from the former French colony of Djibouti with orders to shoot the rogue aircraft down.
But Tango-George seems to have disappeared. In fact, one of her two engines had to be shut off, and a forced landing is made at an airfield near Port Sudan. The Sudanese government, acceding to every demand in order to get the nuclear peril out of their country, sends engineers to repair the faulty engine. Israel plans to raid the airfield at Port Sudan and take over the plutonium. Just in time, Tango-George takes off again, bound for Aden until the hijack leader hears on the radio that Aden airport is closed with its runways blocked with lorries and buses. The hijackers intended to use equipment called a nut-cracker, capable of turning the plutonium into a bomb, at the oil-distillery at Little Aden, and it seemed their comrades in Aden had been ousted from power. Tango-George is almost out of fuel after flying around uncertain where to head, and makes another emergency landing, this time at Jeddah, its original destination. There a Holy Man approaches the aircraft which is parked at the end of a runway, and after an argument with the Hijack leader he is shot. Tango-George takes off again as thousands of Muslims rush the airport intent on tearing apart the killers of the Holy Man.
Meanwhile, a RAF control aircraft has been following in the wake of Tango-George, carrying the British prime minister's adviser on nuclear security. In case the British pilot is involved as seemed the case earlier, he has taken the pilot's old lover and her husband with him. The former lovers' reunion when Tango George is allowed to land at Riyadh, the Saudi capital, is part of a startling denouement.