Very unusual stories. Heavily science- and math-based sci fi (Dad, I think you’re going to want to borrow this) that in some stories felt a bit beyond my grasp, theoretically. (Fortunately the characters keep you involved, even when their minds are on a different plane than yours.) Not necessarily futuristic, although sometimes a touch of it. But not fantastical (along the lines of, say George Saunders); even the wildest ones feel like they COULD be happening.