In 18 short stories rich with regret, turmoil, and strained optimism, Dunmore captures how a single moment can change the course of a life: A bitter father rashly shoots his daughter's best friend; a town bully catches his neighbor in a forbidden kiss. Here, pedestrian details sing entire tales about the characters, as in the case of a visiting Polish teacher stranded in an English school cafeteria: ''His tie... was red with bold green squiggles on it. It was a terribly hopeful tie.'' Not all the stories are so subtly wrought; a few, in fact, clang with obvious themes. But the ones that work, and they are the majority, are much more than mere sweet diversions.