Legend of the Anaconda King (Chronicles of the Moon #3)

The search for more Talismans of the Moon leads Olly (Olivia) and Josh deep into the jungles of South America, this time looking for the missing Amulet of Quilla. But they must brave rockfalls, flames and the mysterious riddles of the Incas to reach the amulet -- and will they get there before it falls into the wrong hands? Also called The Amulet Of Quilla (Talisman #3)