White wolf on a black path: Cossack fantasy

I did not think, did not think the hero of this book, what an interesting journey to him, an ordinary schoolboy Markiyan Kozachenko, smells. But once a Cossack Mamai jumped out of an old portrait hanging in his room. And spun, spun. First, Markian got into the parallel time corridor of Ukraine, then - to Zaporizhzhya Sich, and from there - to Berestechko. During this journey, so many adventures fell on his clever head that you only have time to marvel, to dodge bullets and sabers, to get out of the dungeon of the ancient castle, to discover the secret of the monk Luka's book, and to free Hetman Khmelnytsky himself. But when faithful friends are around, everything can be overcome. And at the same time - to change for the better. Now Markian understands well what the words mean: "The Cossack is not afraid of clouds or quarrels."