A Soviet science-fiction film directed by Aleksandr Mayorov at Mosfilm in 1984, based on Kir Bulychev's novella The Martian Potion from his Veliky Guslyar cycle. In the 17th century the Cossack Almaz Bityi helps an alien whose ship has crashed and receives an elixir of youth in return. Centuries later he returns to the town of Veliky Guslyar, where the remedy is kept; the secret gets out and several townspeople try the potion.
