About the book: year / Archaeologist Semyon Karpov is looking for the treasures of the Atans - an ancient people who had a high culture and disappeared several thousand years ago. The path to the treasure is closely connected with the illogical mathematics of the Atans, in which 2 + 2 in one case equals four, in another - seven, and in a third - one. But only she can indicate where the treasure is hidden in the labyrinth of caves.