According to Chekhov," Tamaru said, rising from his chair, "once a gun appears...

According to Chekhov," Tamaru said, rising from his chair, "once a gun appears in a story, it has to be fired."
"Meaning what?"
"Meaning, don't bring unnecessary props into a story. If a pistol appears, it has to be fired at some point. Chekhov liked to write stories that did away with all useless ornamentation.