Estonian Communist Party boss Romanenko, on a trade mission to Britain, is shot to death in Edinburgh's railway station. His Scotland Yard bodyguard Frank Pagan immediately nabs the assassin, an Estonian-American loner named Kiviranna, but Pagan is thwarted when Kiviranna commits suicide. In quick succession Pagan meets Kristina Vaska, daughter of an Estonian dissident, is shunted off the case by British Intelligence and is almost killed by a KGB assassin. An old Estonian patriotic poem carried by Romanenko and Kristina's tale of a Baltic, anti-Soviet ''Brotherhood'' intrigue Pagan, as does the beautiful Kristina.