The Power of Six is the second book to I am Number Four. This books takes off from the end of I am Number Four when John, his new friend Sam, and Number Six, leave Paradise, Ohio after their previous battle with the Mogadorians. Throughout the book it switches from Johns life to another Guards life, number Eight. Number eight's current name is Marina and her Cepans name is Adelina. When they came from their home planet Lorien, Adelina and Marina separated from the original nine guard and started their journey hiding from the Mogadorians, and waiting for Marina to gain her Legacies, her powers. Adelina and Marina never really found a place to stay on earth and they were soon out of money. Soon they ended up in Spain at a convent that they currently live in now. After being in the convent for a while Adelina forgot what her true purpose on earth was and so Marina had to go through her Legacies on her own. Meanwhile John, Sam, and Six keep running away from cops and keep hiding from the Mogadorians that still hunt them. Will Sam, John, and Six ever get caught and will they ever meet with Marina to find the other Cepan? Keep reading this very excited book to find out what happens next!