THE ADVENTURERS travel to Lisbon during the Christmas holidays and go on a tour of the monuments of Central Portugal. While they are visiting several castles and monasteries, news comes of an audacious diamond robbery in a jewelry shop. Though excited and in a good mood, Bea and Daniel grow suspicious of two mysterious ladies who are also part of the tour and decide to find their secret no matter what it takes. As she tries to further investigate them, Bea finds herself locked inside the Monastery of Alcobaça at night. Then the two suspicious ladies are there too... as well as some haunting, unexplained noises! After maddening chases, hidden staircases, secret passages, and underground rivers, THE ADVENTURERS make an unbelievable discovery! Volume One in THE ADVENTURERS series, The Adventurers and the Treasure Cave, is a Literary Titan Book Award Winner - Four Stars / Silver Award.