'Summer Thunder' is a horror short story written by American author Stephen King It was first published in Turn Down the Lights, (a trade hardcover published by Cemetery Dance to celebrate its 25th anniversary), and later collected in King's 2015 short story collection, The Bazaar of Bad Dreams. The story deals with the end of the end of the world, its main character being Peter Robinson, a survivor. It is similar to King's novel, The Stand, but it focuses more on Robinson's character and how he deals with it, than how the world actually ended.
The world is in a nuclear war, and most of the population has been wiped out. The main character in the story is Peter Robinson, a man in his late forties, whose wife and daughter were in Boston when everyone was suddenly killed. Robinson also finds a stray dog, whom he names Gandalf, and his bonding with the dog helps him cope with the death of his family.
Bit by bit, it's revealed that Robinson has but one neighbour left, an old man called Timlin, who lives in a luxurious cottage called Veronica and who Robinson befriends over the course of time. The story narrates Robinson's emotions and musings, and the advice given to him by Timlin. Timlin has much more knowledge about the radiation crisis than Robinson, and tells him how those who did survive will slowly die of radiation poisoning. He is proven right by the death of most of the animals in the surrounding wilderness, and further so when Gandalf's health rapidly deteriorates.
Robinson later finds Timlin with a gun on his table. Timlin says he is dying of radiation poisoning, but he doesn't want his death to be slow and painful, and hence has decided to shoot himself with the gun. He gives Robinson a hypodermic needle and advises him to put Gandalf out of his misery and not let him suffer. Timlin later kills himself. Robinson, despite his love and concern for the stricken animal, injects Gandalf with the needle.
Robinson himself starts showing symptoms of terminal radiation poisoning the very next day, and he decides to end his life on his own terms as well. He gets his favorite motorcycle, a Fat Bob (whose sound is described as being like summer thunder), running again. He then takes one final, exhilarating ride on it before making a suicidal run directly at a road sign.