Adventure Book collection for teens

Selling a mixed lot of great adventure books for young readers. My son loved these books! Can sell individually as well Set Includes: - Tunnels by Roderick Gordon and Brian Williams - Percy Jackson & The Olympians: The Sea of Monsters by Rick Riordan - Percy Jackson & The Olympians: The Titan's Curse by Rick Riordan - The Fire Within by Chris D'Lacey - Over Sea, Under Stone (The Dark is Rising Sequence) by Susan Cooper - Percy Jackson & The Olympians: The Lightning Thief by Rick Riordan