Amy and Dan Cahill have their final confrontation with twisted billionaire J. Rutherford Pierce, a man whose power has no limits and is one step away from being elected president.

When seven members of their family were kidnapped, thirteen-year-old Dan Cahill and his older sister, Amy, got ready for the fight of their lives. But their enemy, a terrifying group known as the Vespers, remained frustratingly elusive. They stay in the shadows, picking off Cahills one by one. And now the Vespers have landed their most serious blow yet ? A blow that strikes at the very heart of the Cahill family. Because Amy and Dan discover that...

An adventure on the wide open ocean, and Ruby is all at sea. Can she crack the case while evading the clutches of the evil Count von Viscount? Well, you wouldn't want to bet against her.

A million dollars, or a clue? Police report a break-in at an elite hotel, and the suspects sound suspiciously like Amy and Dan. There's a car and speedboat chase and an angry mob! When there's a Clue on the line, anything can happen. "La carrera contrarreloj para encontrar las 39 pistas ha empezado, y los hermanos huérfanos Amy y Dan Cahill no pueden creer que estén a la cabeza de la búsqueda, que los lleva a Viena y Venecia. Pero, ¿lograrán...