"Theo Pincher is good at most things: drawing, tying shoelaces, working the remote control. But he just can't lie--and in the Pincher family, what matters most is being able to lie and pinch things that belong to others. Then his parents decide to visit the diamond exhibition. "Promise you won't pinch the gold diamond?" says Theo. "I promise," says his mother, one hand behind her back. "We'll just take a little look," says Theo's dad. "No touching."...