This films starts with an animated sequence that happens in the 17th century and shows how a boy was captures by a slave boat and taken to a Caribbean island, where he hides a map in a jar, before being taken to work in the sugar cane fields. Now in life action and present day, a family of four in getting ready to leave the house in order to have a picnic near a lagoon. The two friends arrive and they all drive to the Condado Lagoon in San Juan. The children start playing and one of them finds a jar with a map inside. So without their parent's permission, the four children decide to embark on an adventure through the Estuary of San Juan, thinking they will find a treasure if they follow the map. They cross a lagoon on a raft, then they find a sailboat and ask the captain to take them to the other side of the San Juan Bay. From there they walk to a marshland and cross it even though their legs are half way in the mud. Right in the middle of the marshland, they befriend a good witch, who tells them about the story behind the map and the period of time in which children were also forced into slave work. She offers to take them on her jeep to their next stop, in the lagoon on the opposite side of the city and ask her fisherman friend to take them further into their adventure on his motorboat.Finally they take four kayaks to cross another lagoon and so they get to a beautiful mangrove area. They think they have found the treasure where they dig in the mud, but only find a blue glass bottle in the midst of the mangrove trees. These scenes are inter cut with both parents trying to find them, first by notifying the police and jumping into their car and later by taking a helicopter to oversee the different bodies of water in the Estuary. Finally they see them and land in the mangrove area with the help from a ranger.All ends well and they re-unite in a surreal atmosphere, around a gorgeous glass tree.The kids have discovered that the treasure they were looking for, really lies within themselves, their joint talents and nature that they will protect forever.