Douglas hears his brother Tom counting out loud and asks him what is going on. Tom counts the number of times the cicadas buzz in fifteen seconds and calculates the temperature by adding thirty-nine to the number of buzzes. Douglas walks over to a thermometer in the hall and tells Tom that it is eighty- seven degrees Fahrenheit and that there is no need to count. Tom calculates ninety-two degrees and tells Douglas that he is calculating the outside temperature, and the thermometer gives the temperature inside. Douglas argues briefly and then begins counting the buzzes.
Mr. Jonas, the junkman, comes into town with his horse Ned and his wagon. He sings as he rides, and people line the streets to look at his goods. No ordinary junkman, Mr. Jonas had lived as a businessman in Chicago but decided to spend the rest of his life making sure that one area of town got a chance to take what the other side considered junk. He traveled through the town and only asked that people took something that they truly wanted, something they would use. Then the adults of children would put something of their own that they no longer had any use for in the wagon, and Mr. Jonas would be on his way, singing.
The morning is incredibly hot, and Tom goes to get his brother so they can go swimming. He sees that Douglas does not feel well and touches his forehead. Douglas is burning up, and Tom runs to tell his mother that his brother is sick. The doctor comes to see if he can help, but he is unsure what to do. Gripped by the fever, Douglas replays all of the events of the summer through in his mind. He sees all of the sadness, all of the unhappy changes that have darkened the magic of the hot months. Tom sees Mr. Jonas outside and tells him that Douglas is very sick. Mr. Jonas wants to help, but he does not have anything in his wagon that can help the boy. He comes back at seven thirty that night and wants to see Douglas but Douglas's mother sees him and tells him the boy is not awake and that the doctor said he should not be disturbed. Later that night Mr. Jonas decides he must help, and he goes to Douglas's side as he lies on a cot in the yard. He tells the unconscious boy that he has two bottles for him—they contain pure cool air to be drank through the nose on sweltering summer nights. Mr. Jonas wants Douglas to wake up and drink the air. A few minutes later Tom rushes in to tell the rest of the family that Douglas is better.
The next morning the heat finally breaks. Heavy summer rain falls as Douglas lies in bed recuperating.
Tom's method of calculating the temperature gives Douglas a little bit of summer magic, but Douglas seems ambivalent and unsure about his brother's technique. Although he tries to follow Tom's method, Douglas's heart is not in the effort. The magic of summer has faded away, and Douglas no longer knows where to find it. The magic of life threatens to fade away while Douglas is in the grip of a terrible fever. The fever is a metaphor for the mental agony that Douglas has been forced to endure, a symbol of his difficulty in coming to terms with life and death.
Mr. Jonas, the junkman, is a character who wants only to bring people what they want. He knows that what is important to one person is not important to someone else, and he does his best to keep items cycling through the town. There is always something that people want in Mr. Jonas's wagon, and he feels bad when he had nothing that will help Douglas. But Mr. Jonas is a compassionate man who knows Douglas well and thinks that he understands the sorrow that is burning through the boy. He realizes that the summer has become too much for Douglas. All of the summer's events have taken their toll on Douglas, and all of them seem to point to one thing: that he must die someday. But Douglas is a twelve- year-old boy, and he wants desperately to continue living in a world of fantasy and wonder, not a world where all life is fated to die. Mr. Jonas understands what Douglas is going through, and brings him a gift of cool air to drink. The air in the sweltering summer is like dandelion wine in the winter—it brings calm and relief and knowledge that the cycle of things will come around again. To Douglas, for whom the summer had become stifling, this little bit of cool air is a reminder of the winter that will follow the inevitable end of summer. Douglas was wrapped up in the discoveries of summer, and when they threatened to destroy him, he needed the perspective of Mr. Jonas to survive. The taste of winter was more than just the cycle of the seasons. It was also the cycle of life, and that is what Douglas needs to be able to handle.