Watch Online Free on Watchseries. The contents of the Wonderful Doctor’s yellow suitcase cure not only colds and the flu, but also sadness, loneliness, cowardice, and timidity. Petya is a modern, reclusive boy who refuses to go outside; he is afraid of society and other children. His parents decide to turn to the Wonderful Doctor, but his magic suitcase is stolen. From that moment on, a series of adventures begins.