The events of the novel "Blood Sisters" develop in Gdańsk, on the Ukrainian corsair ship "Strybog", which hunts Spanish galleons, and, of course, in Lviv. It mostly features the same characters as in the novel "The Apothecary", although new ones have also appeared. However, if in "Apothecary" the main character was the doctor Lukash Gulevich, then here it is Juliana, who disguised herself as Lorenzo's boyfriend in order to take revenge on her sister's killers.
From the moment the "Devil's Bible" was discovered in the Bernardine monastery, both the Pope and Queen Christina of Sweden were immediately interested in it, and they are still trying to get it.
Intrigue to the plot is added by the arrival in Lviv of the Spanish Prince Juan, who hires Cossacks to win the throne, and the appearance of the mysterious Order of the Sisters of the Holy Blood.
Fights, sea battles, ordered murders... And all this against the background of the desperate defense of Lviv against the troops of Bohdan Khmelnytskyi in 1648. It is also interesting that for the first time in literature these events are described not through the eyes of Ukrainians, Poles or Jews, but through the eyes of Lviv residents.
