Isobel Sadler is dead broke. The only thing she's got that might bring in any money is a stupendously bad painting that's been in her family for generations. It's so ugly she can't imagine it would be worth much, but the other night someone tried to steal it. Mystified, she turns to art dealer Michael Whiting, who identifies the painting as a 16th-centurytreasure map, pointing the way to a cache of priceless religious artifacts that were hidden by...