KC and Marshall investigate the theft of a precious emerald, brought by representatives of the Chinese government to bring luck to two baby tigers born at the National Zoo.

The absent author: Dink Duncan and his two friends investigate the apparent kidnapping of famous mystery author Wallis Wallace. The bald bandit: Third-grader Dink and his detective friends hope to receive a big reward by finding the person whose video recorder picked up a picture of the local bank robber. The canary caper: Dink and his friends investigate why pets, like Mrs. Davis's canary, Mozart, are mysteriously disappearing all over town.

KC and Marshall take a tour of the Bureau of Engraving and Printing, and when they discover that someone has been stealing bricks of newly printed money, they resolve to find the thief.

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 collection of calender mysteries.

KC and her friend Marshall accompany KC's stepfather, the United States President, to remote Camp David, where they find clues that point to either ghostly or criminal activity.