The President of the United States is hosting a massive, important celebration at the Lincoln Memorial, and KC and Marshall are right in the middle of the excitement. They are helping to honor the talented, famous sculptor who created the massive marble statue of the former president. But as they look closely at Abraham Lincoln's giant hands, they notice something terrible has happened. The giant left thumb has been completely broken off and stolen by an unknown vandal. With the big, televised ceremony quickly approaching, the two best friends have to spring into immediate action. Join KC and Marshall as they race frantically across Washington DC to track down the missing marble thumb before it is too late to fix the statue. You will get to explore famous national monuments and piece together the clever clues to save the historic celebration from total disaster.