"Mike" (Tyrone Power) is a US State Department courier who is sent on a routine, but dangerous, mission to Trieste where he is to rendezvous with a passenger on a train then collect and repatriate an important document. Of course, the Soviets are also on the trail of this transaction and when it all goes wrong, "Mike" finds himself embroiled in something far more sinister than he has experienced before. He is now at the behest of his new military handler "Col. Cagle" (Stephen McNally) and his wily sergeant "Guelvada" (a lively effort from Karl Malden) as he must try to find which of two women - "Janine" (Hildegard Knef) or "Joan" (Patricia Neal) might be mixed up - or not - in this espionage drama with more crosses than a Papal mass. Now I found the mystery here a little lacking. Serendipity just takes too an implausible a role in a wine bar and from there on in I felt that the jeopardy was rather compromised. Still, Henry Hathaway uses this workmanlike cast to good effect helping to create an atmosphere of mistrust and peril with nobody quite sure who is trustworthy and who is just as likely to put a knife between the shoulder blades. Trains also usually serve well as vehicles for thrillers - the movement, dimly lit carriages and squeaky rails all contribute to the heightened sense of tension as we near the reveal. Perhaps if you don't spot the huge great clue early on, you might get more from this well paced thriller.