If you like Percy Jackson and the Olympians, as well as Heroes of Olympus, try:

• The Red Pyramid (part 1 of The Kane Chronicles)
• The Ruins of Gorlan (part 1 of The Ranger’s Apprentice)
• The Spook’s Apprentice (part 1 of Spook’s, aka The Wardstone Chronicles)
• The Recruit (part 1 of CHERUB)
• The Colossus Rises (part 1 of Seven Wonders)
• Artemis Fowl (part 1 of Artemis Fowl)