The drunken doctor Pyotr Ivanovich hatches a scheme: with two spiteful letters, he pits the arrogant boss Burov against his brother, the artist, over the price of a painting and an old grudge. Meanwhile, the foundling Petya recounts how Andrey Ivanovich, who was painting Saint John using him as a model, suddenly noticed a birthmark on the boy, trembled, grabbed him by the throat, and demanded to know who his parents were — and then burst into tears. A note arrives: "Who is this boy, where is he from?" The mystery of the wolf cub's origins deepens.