Build a movie plot around this: WHERE DO THE POLICE STOP THE TRAIN? ON THE FOURTH BRIDGE .
The answer to this question is:
At a London music hall theatre, Richard Hannay (Robert Donat) is watching a demonstration of the superlative powers of recall of "Mr. Memory" (Wylie Watson) when shots are fired.[1] In the ensuing panic, Hannay finds himself holding a seemingly frightened Annabella Smith (Lucie Mannheim), who talks him into taking her back to his flat. There, she tells him that she is a spy, being chased by assassins, and that she has uncovered a plot to steal vital British military information, masterminded by a man with the top joint missing from one of his fingers. She mentions the "39 Steps", but does not explain its meaning.Later that night Smith, fatally stabbed, bursts into Hannay's bedroom and warns him to flee. He finds a map of the Scottish Highlands clutched in her hand, showing the area around Killin, with a house or farm named "Alt-na-Shellach" circled. He sneaks out of the watched flat disguised as a milkman and boards the Flying Scotsman express train to Scotland. He learns from a newspaper that he is the target of a nationwide manhunt for Smith's murderer. When he sees the police searching the train, he enters a compartment and kisses the sole occupant, Pamela (Madeleine Carroll), in a desperate attempt to escape detection. She frees herself from his unwanted embrace and alerts the policemen, who stop the train on the Forth Bridge. Hannay escapes, however.He walks toward Alt-na-Shellach, staying the night in the house of a poor crofter (John Laurie) and his much younger wife (Peggy Ashcroft). Early the next morning, she sees a police car approaching and warns Hannay. Hannay flees, wearing the crofter's coat. At a bridge, he finds a sign for Alt-na-Shellach. He arrives at the house of the seemingly respectable Professor Jordan (Godfrey Tearle) and is let in after saying he has been sent by Annabella Smith. The police arrive, but Jordan sends them away and listens to Hannay's story. Jordan then reveals that he is missing part of a finger; he shoots Hannay and leaves him for dead.Luckily, the bullet is stopped...