As she does every year, Agatha Howard comes to the grave of Dr. Juan Munoz to leave flowers and recall the events of their relationship and what led to his death nearly fifty years ago...
In 1923, Agatha arrives at the apartment home of Dr. Munoz, a widower and friend of her late father's. The landlady, Mrs. Gibbons, tolerates the doctor even though he has a machine in there that's always running and sometimes keeps the other tenants awake. Upon meeting him, Agatha finds Dr. Munoz, who once lived in Spain, very charming and fascinating. Inside the apartment, Agatha notices that the apartment is very cool, around 55 degrees, due to a refrigeration machine.
The two discuss her father and their theories about death, in which death can be staved off by sheer, human will. As for the machine, Munoz explains that he contracted a rare illness; exposure to higher temperatures will kill him.
Throughout the summer, Agatha visits Dr. Munoz frequently, falling in love with him. One hot day, Agatha knocks at his door, but Dr. Munoz refuses to let her in; he's having trouble with the refrigeration unit and he cannot see her. On the way out, Mrs. Gibbons wants to know what's going on; a repairman came by earlier to fix the machine inside Dr. Munoz' apartment, but left in a dead run. Agatha has no idea why.
The heat is replaced by a summer thunderstorm that night. Dr. Munoz calls Agatha, pleading with her to come over. She arrives at the apartment, but Dr. Munoz won't let her in. He says through the door that the refrigeration unit has broken down and he can't fix it, and pleads for a repairman. Agatha finds a repairman in a downstairs apartment. Dr. Munoz, dressed in a robe and holding a towel over his face, lets them in. The repairman says a part on the machine is broken and a replacement part won't be available until the morning. After the repairman leaves, Dr. Munoz tells Agatha that morning will be too late for him. He asks her to get him some ice. Three hundred pounds are delivered to him inside his apartment's bathroom and he locks himself in with it, but he knows the end is near for him.
Agatha pleads for Dr. Munoz to let her in, but he won't. He reveals to her that his theory of forestalling death by sheer will has proved to be true, but at a price. His internal organs have decayed. As for the cold air, it has preserved him all this time, but it can only do so for so long. He also says that his wife died by suicide because she couldn't stand living with a corpse - because he died ten years ago.
Agatha hears him fall inside. She manages to open the bathroom door - and screams. Dr. Munoz is dead on the floor, his corpse rotting as if it had been dead for over ten years....
Back in the present, the wind blows leaves off the gravestone of Dr. Juan Munoz. It's inscribed: Born 1877. Died 1913...and 1923.