From publisher blurb:
Over three decades ago, the only child of Dr. Rudolph van Richten was stolen by Vistani thieves and sold to a vampire. The doctor's efforts to rescue his son and then avenge himself upon that vampire led to a dark new career fighting the terrifying monsters in the Demiplane of Dread. Now, the sage of Ravenloft turns his attention to the very people who made him what he is today.
In spite of his deepest fears and hatreds, Van Richten has passed among the Vistani—the nomads of the Mists—and he has learned much. Within this book he describes Vistani legends, their everyday life, abilities common to all of them, and some of the fell powers possessed, fortunately, by only a few. Van Richten also identifies each of the Vistani tribes, their strange and special powers, and their habits and beliefs.
In addition, an appendix is provided for the generation of Vistani player characters.