The Power of Six by Pittacus Lore

John Smith, Garde Number Four is on the run from the vile Mogadorians but without his trusted mentor Henry. Meanwhile, Marina, Garde Number Seven, waits friendless in a Spanish convent for her 18th birthday, so she can leave and seek out the other members of the Garde. Helen Carter reviews The Power of Six by Pittacus Lore (pseudonym of James Frey and Jobie Hughes) – an engaging follow-on from I Am Number Four.