Nun Pelagia has a sharp mind and a real gift for being a detective. Therefore, Father Mitrofaniy sends her to his aunt's estate to investigate the mysterious murder of white bulldogs. Just at this time, another crime occurs in the area, but it is much worse: a man and a boy are killed and beheaded. And this is far from the last violent death that will happen in the area. Suspicion falls on the local pagan Zityaks. Pelageya will have to conduct her own investigation and find out who is really guilty of the terrible crimes. Monakhini︠a︡ Pelagii︠a︡ (v miru Polina Lisit︠s︡yna) obladaet ostrym umom i nastoi︠a︡shchim darom syshchika. Poėtomu otet︠s︡ Mitrofaniĭ napravli︠a︡et imenno ee v imenie k svoeĭ tetke, chtoby rassledovatʹ zagadochnoe ubiĭstvo belykh bulʹdogov. Kak raz v ėto vremi︠a︡ v okruge proiskhodit eshche odno prestuplenie, no uzhe kuda strashnee: muzhchinu i malʹchika ubivai︠u︡t i obezglavlivai︠u︡t. I ėto daleko ne posledni︠a︡i︠a︡ nasilʹstvennai︠a︡ smertʹ, kotorai︠a︡ sluchitsi︠a︡ v okruge. Podozrenie padaet na mestnykh i︠a︡zychnikov-zyti︠a︡kov. Pelagee predstoit provesti svoe rassledovanie i uznatʹ, kto na samom dele povinen v strashnykh prestuplenii︠a︡kh.