Martin, a poor student, volunteers to go on a quest to find a cure for the princess Adriana, who is stricken with a strange illness. Unknown to Martin or anyone else, the princess is actually under the spell of the powerful magician Andlobrandini, who is preparing a rejuvenating elixir made from the blood of nine men's hearts.

When famous detective Nick Carter visits Prague, he becomes involved in strange case of a missing dog and even stranger carnivorous plant. He becomes convinced that he is standing against his greatest enemy, the Gardener, who supposedly died years ago in a swamp...