American scientist Michael Armstrong defects to Eastern Europe, followed by his reluctant fianc￿Sarah Sherman. It's no surprise to learn that the defection is not genuine, and that his real mission is to steal a secret mathematical formula from a professor in Leipzig.

Director Cameo: [Alfred Hitchcock] early in the film sitting in a hotel lobby with a baby on his knee. He transfers the baby to his other knee, and then rubs his knee, as if disdainfully looking at something the baby has done to it.

[first lines]


Professor Karl Manfred:
Are they ever going to get the heating fixed?


Norwegian crewman:
They are working at it, Professor. Perhaps some of you scientists would like to give us a helping hand!

Factual errors: A few snippets of dialogue in the scenes in the East German university clearly show that the extras are Americans.

Music by Johann Strauß
Played at the restaurant