Thriller novelist Eric Ambler, often credited with elevating the spy genre to the level of esteemed literature, was introduced into the film business while serving in World War II. He worked with luminaries such as Carol Reed and Peter Ustinov in the Royal Army Film Unit, producing propaganda movies like "The Way Ahead" (1944). Before he turned scriptwriter, the author's fiction was brought to the screen in film adaptations of his novels including "Journey Into Fear" (1942) and "Hotel Reserve" (1944). Also in 1944, Peter Lorre starred in "The Mask of Demetrios," a thriller based on Ambler's 1939 novel "A Coffin for Demetrios." Both the film and the novel enjoyed popularity and acclaim, and Ambler's Balkan set story has even been called prophetic, as the novel mirrors the political upheaval in the area that occurred decades later.