George Saunders captures the fragmented rhythms, disjointed sensory input, and wildly absurd realities of the 21st century experience like no other writer. He is satiric without being sarcastic, ironic yet compassionate. He mocks the bizarre institutional structures we’ve created — mindless bureaucracies, stale theme parks (in his 1996 first collection, “CivilWarLand in Bad Decline’’), immoral goals promoted in rah-rah corporate technotalk, without being contemptuous of his characters. His prose mimics how we think, with abrupt starts and stops, the interior flow of perception interrupted continuously by digital cues and exterior shocks that require immediate analysis: Quick, a stranger at the door. Danger?

“Victory Lap,” the first story in “Tenth of December,” his bold and moving fourth collection of short stories, opens when a girl “three days shy of her fifteenth birthday” takes her place at the top of the stairs and wonders about the “special one” in her future. Alison is given to romantic fantasies and ballet references (she has a recital coming up that night).