Black Widow — Carolyn Keene

A romantic cruise to Rio sweeps Nancy into a carnival of crime

Carson Drew takes Nancy on a cruise to exotic Rio de Janeiro. Once on board the Emerald Queen, a beautiful widow named Nina da Silva seems to attract his attention. The problem is, Nina happens to be Nancy's top suspect in a strange case of stolen gems.

During her investigation someone tries to kill Nancy with a poisonous spider. Then handsome cruise director Randy Wolfe is wounded by a poisoned dart meant for her. Amid the glittering excitement of Carnival, the teen detective is stalked by a phantom hit man -- who wants Nancy stopped before she can uncover the priceless treasure of the Emerald Queen.