American agent Raft, pretending to be a machinery salesman, travels to Turkey via train, where he meets sophisticated Massen, who thrusts secret documents on him before she is murdered in an Ankara hotel room adjoining his. The envelope she has entrusted to him contains oddly marked maps; just after she hides them, agents burst into Raft's room and take him at gunpoint to see Nazi master spy Greenstreet. He demands the maps, which show where German troops will invade Turkey, just after that neutral government has been alienated from its unofficial ally, Russia, through another series of plots. When Raft refuses to turn over anything, he is mercilessly beaten, but before Nazi goons kill him he is rescued by Lorre and his sister, Marshall, who tell him they are Russian agents, also seeking the maps. But Raft no longer has them; they have been stolen by Greenstreet's agents. The American invades the fat spy's lavish estate, where he finds Lorre and Marshall held prisoner. Raft manages to free himself and Marshall from the Nazi clutches with the help of Lorre, who sacrifices himself so they can escape at the last minute. A curve-slicing car chase ensues with Raft racing after Greenstreet, catching him, compelling him to destroy the secret plans, then sending him on his way back to Berlin, where all know he will be imprisoned, perhaps executed, for his failure. The fat man goes off, wincing at his fate and Raft, with Marshall on his arm, "cements Russian-American relations" by heading for Cairo. The film is quick-paced and properly moody in lensing, having all the ambiance of an Eric Ambler thriller, this being his second spy book to be converted to the screen (albeit the first, JOURNEY INTO FEAR, is a far superior production). The story is confusing at times, and bogs down in the middle, where it's difficult to tell who is spying for what country, but the presence of the volatile Lorre and the sneaky Greenstreet, the most perfect pair of rascally spies, overshadows the occasional lassitudes. Raft is very good as the American agent, though he at times seems colorless, but then he has to contend with fascinating scene stealers Greenstreet and Lorre. Ironically, this film was made as a follow-up to Warner Bros.' immensely popular CASABLANCA: Raft had originally turned down the role Bogart played in that classic and when he tried to duplicate Bogie's character, he and BACKGROUND TO DANGER fell short of the success of its predecessor.