Mystery at the Washington Monument

When KC and Marshall see lights flickering at night in the Washington Monument, their investigation turns up a monkey, a hole in one of the monument stones, and a hundred-year-old mystery. Late at night KC and Marshall are sleeping out on the White House lawn when they see suspicious lights flickering at the top of the Washington Monument. If that's not strange enough, the next day a monkey is found inside the building! KC and Marshall set off on a wild adventure to solve a 100-year-old mystery that involves a jewel thief, long-lost diamonds, and one of Washington's most famous and historic landmarks.