After I’m Gone by Laura Lippman Wm Morrow/Harper Collins, $26.99, 334 pages, ISBN 978-0-06-208339-5 Have you ever played the WHAT IF game?  You know . . . the one that goes like this . . . What if I lost my job?  What if one of us gets sick?  Really, really sick like Ebola or something?  What if a UFO landed behind our house?  What would we do .