Rudolf Steiner, a handsome young man, was an adventurer. One evening he walked around the city center. Near the dentist’s sign, he saw a huge growth of a black man in a fantastic clown dress, which was handing out some leaflets to passers-by. He handed one of the sheets to Rudolph. One side of the sheet was blank, and on the other it was written: "Green door." One of the passers-by, taking a leaf from the Negro, threw it on the sidewalk. Raising it, Rudolph saw that there was an advertisement for a dentist. The spirit of adventure prevailed and Rudolph again walked past the black man, who again handed him a leaflet with the inscription "Green Door". On the sidewalk lay an advertisement for a dental office. Rudolph decided that he was chosen among the crowd. The building in which the secret green door was located was five-story. On the third floor, he saw a green door. At his knock came a pale girl who barely stood on her feet. Seeing Rudolph, she fainted.

Rudolph laid the girl on the bed and looked around the room, the situation of which spoke of extreme need. Recovering, the girl admitted that she had not eaten for three days. Realizing that this was the most amazing of all his adventures, Rudolph rushed to the nearest restaurant and brought all kinds of food.

During the meal, the girl told her simple story. She worked as a saleswoman in a store, received a miserable payment, also cut down by the fines of the owner. Then she got sick and was fired from her job. She has no friends or relatives, and an adventurer knocked on her door. Young people realized that they had found each other. Rudolph promised to drop by tomorrow to visit the girl.

Going out onto the stairwell, he went up higher and saw that all the doors in the house were green. Once on the street, he went to the black man and asked why he gave him the leaflets with the inscription "Green Door." In response, he was shown a theatrical entrance, above which was an advertisement for a new production of The Green Door.

- I heard that the play is first grade. Their agent gave me some pieces of paper so that I would hand them out along with the doctor’s advertisement, the Negro said.