Stephen Marlowe 
Drumbeat – Berlin [EPUB ebook] 

An old flame’s fiancé is missing, and only Drum can save him from the Soviets Chester Drum will never love another woman the way he loves Marianne. After years of on-and-off romance, he tells her that his work as a private detective is too dangerous for him to ever marry, so she ends the affair and moves to West Berlin, to report on the Cold War from its front lines. There she falls in love with Quentin Hammond, ace foreign correspondent, and Drum is happy for her until her new man disappears behind the Iron Curtain. She telegraphs for help, and Drum is on the next plane. Hammond was close to winning the scoop of the century, by cooperating with an exiled East German dissident to tunnel beneath the Berlin Wall and free thousands of people from the other side. Before they could complete their audacious scheme, though, the Stasi kidnapped them. Only Drum has the skills to go behind the wall and return with the man who’s stolen the woman he loves.