Bobby Conroy's made a lot of mistakes; the biggest, perhaps, was when he let Harriet Rutherford slip away from him. And now the two of them - and Harriet's young son - are all extras on the set of Dawn of the Dead, and Bobby has the chance to see what could have been . . .Joe Hill is the New York Times bestselling author of NOS4A2, Horns, and Heart-Shaped Box, and the prize-winning story collectio...