With the Cuban Missile Crisis in full swing bringing the world to the brink of nuclear war Berlin finds itself a divided city with the western sector surrounded by a wall separating it from Russian controlled East Germany. A series of unexplained explosions on the East German-Polish border leads to increased tension between the Allied forces inside West Berlin and the Russian masters of East Germany. A mysterious Lorelei demands a ransom to cease the bombings and the matter is referred to MI5 as it transpires Operation Lorelei was a German plot predating WW2 and revealed by Rudolf Hess during his debriefing following his flight to Britain. Deciding it to be irrelevant Churchill did not follow up on it. Charlie Spicer, British Army explosives expert is commissioned by MI5 to interview Hess in Spandau prison hoping for a lead to finding and stopping Lorelei.
Meanwhile KGB major Nikolai Buirski is also on the trail of the bomber aided by a female assassin, their mission quickly crossing paths with that of Spicer.
The fugitive bomber is part of a Wehrmacht demolitions team that planted the bombs in 1938 and one of the few survivors of the Russian prisoner of war camps following capture at Stalingrad. While the British stall he initiates further explosives while the chasers are puzzled as to the seemingly random nature of the targets -- sites that once housed military significant targets now long irrelevant.
A group of Neo-Nazis led by an erstwhile SS general are behind a series of bank robberies in West Berlin while an Israeli Mossad squad plan to kidnap the leader, a war criminal and take him to Israel. This team form part of Lorelei's escape plan and the plot thickens as the CIA become involved.
Reluctantly working together Spicer and Buirski follow up the clues while pressure from their masters build up. The chase takes them into East Berlin and hot on the trail of Lorelei.
The pace builds relentlessly as the body count mounts leading to a final confrontation in Berlin's Tiergarten Park where a violent shootout occurs during the exchange of the ransom for a notebook containing the key to further hidden explosives.
discovering that he has been tricked, the money being counterfeit, Lorelei threatens to activate the mysterious Target One, which is not listed in the notebook now in the possession of Spicer and Buirski.
With the CIA in furious pursuit and the SS general kidnapped by Mossad the two men realise they have to find Target One and stop a vengeful Lorelei who is now headed there. Also in the chase is one of the SS Nazis who is after the real money which Spicer knows has been swapped for the fake notes by his MI5 controller, the money still in Berlin.
A furious final confrontation takes place on the roof of the Russian Embassy in East Berlin where Lorelei is finally stopped.
Spicer and Buirski part as grudging friends and Spicer traces the MI5 chief to a small hotel in Berlin where the latter is waiting for an expert to arrive to deactivate the money bag he suspects is booby trapped
At that moment they are surprised by the trailing SS officer who is tricked by Spicer into opening the bag, the subsequent explosion of the dye pack covers everything in yellow paint. The Nazi is shot by the MI5 operative and Spicer wistfully decides there are no winners in this game after all.