Things haven't gone so well for Ulysses, Cassie, and Professor Castillo since their return from the Amazon jungle. The story of their adventures in the Black City is so unbelievable that they're reviled by the public and branded as frauds, turning what should have been a great triumph for them into a dramatic setback. In order to prove they're telling the truth and get their lives back, Ulysses and his two companions are forced to embark on a new journey into the unknown in search of irrefutable evidence that will corroborate their story. The trail of breadcrumbs they follow will lead them to one of the most desolate, dangerous, and inhospitable places on the planet … but it's only the beginning, the jumping-off point for an amazing journey full of action, suspense, and mind-blowing discoveries. Ulysses, Cassie, and the professor are determined to risk everything in their quest to unravel the greatest mystery in history. Join them as they set out on an expedition that will take them on the most incredible adventure of their lives in search of the last revelation.