In French, you can use the word “flash-back” (It has recently been added to the dictionary). But as the French don’t like so much all Anglicisms, you can find a side note, clarifying: On préfèrera Retour en arrière. (We prefer Retour en arrière.)
Today, I read a story, which is quite a nice “flash-back”, illuminating our current “spy world”… just technology has a little bit changed.
It’s the story about Acoustic Kitty.
Beware of cats!