What is the second lie that Faith decides to tell the tree, and how does the tree react to her lie?

Faith decides that her second lie should create division among the scientists at the excavation site. There are stories on the island of smugglers who hid treasure there, and a ghost that tries to lead people to it. Faith tells the tree that the scientists at the site are actually looking for that treasure, and that they plan to keep it all for themselves. When she reemerges into the sunlight, tiny pieces of a leaves from the Mendacity Tree burst into flames, and she has to put them out by splashing ocean water on herself.