Merry Anders was playing with fire

Why did a dying man collapse on her, a pair of thugs try to kidnap her from the staid Smithsonian Museum and a powerfully built stranger help fend off her attackers--then vanish?

When Merry caught up with her daring rescuer, infectious- disease specialist Simon Temple met her question in kind. Simon told a strange story about the Museum's newest acquisition. Known as the Fire Diamond for its brilliant red center, the fabulous gem left a trail of dying men in its wake.

Simon was tracking the mysterious malady, but it was more than professional interest that prompted his chilling question: how was Merry feeling?