Private detective Igor Gladyshev decided to spend his vacation in the Spanish town of Susanna Cruz. There he met a group of Russian tourists, and together they went on an excursion to the famous local cave. As soon as the tourists descended into the dungeon, a monstrous explosion occurred. The guide died, the cave partially collapsed, and Igor and his comrades had to look for another way out. While exploring the cave, they came across an ancient skeleton in one of the grottoes. A bony hand clutched a scroll, which described in detail the place where the legendary treasure of Christopher Columbus was hidden...