Editor’s Note (Jan 17, 2012): Lynne Tillman’s story collection Someday This Will Be Funny, from which this story was excerpted at NC last spring, was named one of the best books of 2011 by Publishers Weekly. Here’s a sly, witty, fiercely intelligent, sexy, hilarious, knowing, playful and wise short story, “The Substitute,” from Lynne Tillman’s