Hide and Seek by Kate Messner

When the ancient Jaguar Cup disappears, three kids race through the rain forest to reclaim it!Jose, Anna, and Henry are junior members of the secret Silver Jaguar Society, sworn to protect the world's most important artifacts. When they discover that the society's treasured Jaguar Cup has been replaced with a counterfeit, the trio and their families rush to the rain forests of Costa Rica in search of the real chalice. But when the trail runs dry, new mysteries emerge: Who can they trust? Is there a traitor in their midst? With danger at every turn, it will take courage, teamwork, and a little help from the creatures of the rain forest to keep the cup from falling into the wrong hands.