Various locations in the USA
- Pearl can’t believe that Klaus might be involved with the kidnapping of Tara Sai. A ransom note arrives, demanding the plans to a “Project Nimbus.” Pearl contacts her grandfather who tells her that Project Nimbus was a highly secret military project that Tara created.
- With the FBI’s help, Pearl and Luc discover that one of Klaus’s informants has been tracked coming into the U.S. and is headed to a town called Keystone in South Dakota. They trail the Informant to the small town and learn that he has taken a bus south to look for work as a laborer. In the area where the informant got off, Pearl and Luc are suddenly attacked by a crop duster airplane.
- They split up with Luc telling Pearl to meet him at nearby Mount Rushmore, which is still in the early stages of construction. After eluding the plane, Pearl and Luc arrive at Mount Rushmore and discover clues that lead them up to a hidden doorway set in the back of President Washington’s head.
- The door has a Masonic seal on it and through deduction and a bit of luck they manage to open the door. It’s the entrance to a secret vault holding some of America’s greatest and most cherished documents and artifacts. And just inside the door... is the body of Klaus’s informant — killed by an overdose of the very medicine that Captain Vogel delivered to the orphanage.
- Ransom Note
- Newspaper Clipping
- Climbing Gear
- Door to the Secret Vault