This was Simone Signoret's first English-language film.
The title of the film is a quote from Childe Harold's Pilgrimage by Lord Byron - "Yet, Freedom! Yet thy banner, torn, but flying. Streams like the thunder-storm against THE WIND" (Canto iv, Stanza 98).
John Slater was only 32 at the time although playing a character at least 20 years older.
The aircraft making the parachute drop is a Handley Page Halifax B.III.
The aircraft that does the pickup is a Westland Lysander, regularly used for such clandestine operations.