Nadezhda Lebedeva loved solving riddles. Not puzzles and crosswords from weekly newspapers and magazines, but riddles that life itself throws up. Having accidentally met a young artist on the subway, Nadezhda found herself involved in a mysterious story rooted in the distant past. In her hands was a mysterious artifact - a Japanese box with the secret of Himitsu Bako. Opening it is not so easy; to do this you need to solve a number of difficult puzzles. But is it worth doing this at all? After all, no one knows what secret this elegant object holds. But the eternal female curiosity and adventurous nature prevail over caution, and this leads to the most unpredictable and stunning consequences...