No one knows what really goes on in a marriage, so complex and contradictory are human needs and desires. Usually, the misunderstandings are unintentional (and mutual), the inflictions of pain accidental. That's why Shadow Tag, by Louise Erdrich, is astonishing in its depiction of Irene America, a woman who deliberately sets out to manipulate her jealous, controlling artist-husband, not by simply betraying him but by writing and "hiding" a fictional diary that only suggests infidelity. Everything we learn about Irene's fractured family comes via this fake journal, and from another supposedly honest notebook that she stashes in a safe-deposit box. There's also some narration that seems to be providing unbiased perspective. But like Irene, we soon learn that emotional truth is hard to come by, that love can be perverse, and that even when there is trickery involved, marriage is never a game.