The End of Something seems to be a fairly common story of a boy breaking up with a girl. Very little actually happens. It is the way the characters react, and how the setting mirrors the action, which give the story its intensity and depth.
The story starts with setting the scene. Hortons Bay was once a busy town based around a mill where logs were cut into planks. The planks were taken away by schooners - a type of small sailing ship - which is quite old-fashioned.
One year there was no more timber, so the mill closed. Everything was taken away from the mill, and the town eventually closed down, too.
Ten years later, the mill is just a ruin. Nick and Marjorie are 'trolling' - rowing past while fishing - on their way to set night-lines to catch trout. They talk about the ruin.
The couple carry on rowing along the shoreline, but the fish are not biting. Nick seems to be reacting negatively to anything Marjorie says, or anything that happens.