A young Czech girl (Margaret Lockwood) escapes from a German concentration camp and joins her scientist father (James Harcourt), now a refugee, in England. But when they are kidnapped by German agents and sent back to Germany, a British agent (Rex Harrison) volunteers to go undercover in Germany and retrieve them. Comparisons to Hitchcock's THE LADY VANISHES from two years earlier are inevitable. In addition to sharing the same leading lady (Lockwood), Basil Radford and Naunton Wayne play the same characters they played in the Hitchcock film though they're nowhere near as amusing this time around. Add to that that both films have train settings and Brits attempting to foil Nazi plans, well..... If one doesn't dwell on the somewhat improbable plot too much, it's a first rate thriller. The director Carol Reed keeps pushing his movie faster and faster (with splashes of humor along the way) until the nail biting chase and cable car finale. The young Harrison is enormously appealing and Paul Henreid makes for a credible double crossing Gestapo agent. With Felix Aylmer and Roland Culver.