They are to meet someone who is working both sides and can help them. They are in rooms 234 and 235. This is where Ashenden meets his “wife” Elsa, all part of the cover. Of course, we think of The Spy Who Loved Me where Agent Triple X is posing as Bond’s wife, Mr. and Mrs. Sterling, and From Russia With Love where Bond is traveling with his wife, the Russian cipher clerk, Tatiana Romanova, as Mr. and Mrs. David Somerset. Even in You Only Live Twice as Bond “marries” Kissy Suzuki.
There are many instances where events in an older spy movie will influence future spy movies, like this! In the clip below, Brodie (Ashenden) meets his “wife”, and another gentleman, Marvin, for the first time. Notice the lighting and the camera angles all add to the mystery, confusion, and intrigue in this scene.