The story opens with the protagonist, identified only as the "Patient," being forcibly carried into the insane asylum. Once there, he no longer protests, but seems to accept his incarceration in the huge, overcrowded hospital. The doctor and other staff members seem particularly kind. Because the Patient rapidly loses weight, despite his good appetite, he receives a special diet.
The Patient notices a single scarlet flower among the many beautiful flowers in the hospital garden. He suddenly realizes that all the evil in the world is condensed into the scarlet flower. His mission is to destroy it. But when he attempts to pick the flower, hospital personnel prevent him from doing so, since picking flowers is prohibited. Eventually, he manages to destroy the flower, but notices a second scarlet blossom in the garden. He destroys that one as well, but a third scarlet flower appears. Finally, the Patient sneaks out at night to deal with the third flower, and then is found dead in the garden the next morning, clutching the remains of the scarlet blossom.
