The Dark Frontier launched Eric Ambler's five-decade career as one of the most influential thriller writers of our time.

England, 1935. Physicist Henry Barstow is on holiday when he meets the mysterious Simon Groom, a representative for an armaments manufacturer. Groom invites the professor to Ixania, a small nation-state in Eastern Europe whose growing weapons program threatens to destabilize the region. Only after suffering a blow to the head--which muddles his brain into believing he is Conway Carruthers, international spy--does the mild-mannered physicist agree to visit Ixania....

Winner of the Crime Writers' Association Gold Dagger Award

Syria, 1970. Michael Howell has kept his family's Middle Eastern business enterprises going through a decade of takeovers, war, and revolution, thanks in part to his office manager, Teresa, who is also his mistress. One late night at the office, they discover men working overtime--producing unauthorized bombs for the Palestine Action Force. Worse, this guerrilla terrorist group is not deterred by their discovery--rather, they will enlist Howell and Teresa's unwilling help in carrying out their plan.