A film by Andrei Tarkovsky
Sometime in the mid-eighties, Tarkovsky directed a dystopian Cyberpunk thriller with thought-provoking existential themes.  The film had not yet been released when the Russian government intervened in the post-production, burning the negatives.
After Tarkovsky's death in 1986 it was thought to be lost forever.
However, an immaculate print was discovered in 2022 and is currently undergoing a full 4K restoration, so this visionary work can finally be seen and get the recognition it deserves.