The Gallbladder Angel

Surgeon Vadim Kazachenko operates on the famous writer Sergey Grekov and brings to light a stone that turns out to be... a diamond with the figure of an angel inside.
There is no scientific explanation for the find, and to avoid... being thought of as crazy, the young doctor doesn't tell colleagues or the patient about what happened.
Vadim keeps the stone for himself — and he begins to experience extraordinary luck. A profession that barely allowed him to make ends meet now brings a substantial income, Kazachenko becomes a renowned surgeon, and even the beautiful neighbor Margo reciprocates his feelings... In contrast, the writer Grekov's life collapses into pieces — dragging everyone around him into the abyss.
Step by step, the mysterious stone, whose history goes back to a distant medieval past, treacherously travels from one character in the novel to another, involving its owners in a strange and cruel game.
And each subsequent owner must make a choice. The only problem is that the price of this choice turns out to be unreasonably high...