My guest this week is one half of a collaborative writing team known as ‘Christoph Martin’ – which is actually the two minds of Libby O’Loghlin and Christoph Martin Zollinger. Together they are writing the Expansion series of four political thrillers, and music became a common language that helped them keep their ideas in tune. Spanish-language pop from Nicky Jam helped establish some of the locations; Benjamin Clementine suggested a plot twist; and when a character faces terminal illness, David Bowie’s final album Black Star was a guiding light. Drop by on Wednesday for their Undercover Soundtrack.