Cody, Queen, Luke, and M.E. are the Code Busters—clever clue hunters with a passion for puzzles. They can't wait for their school trip to Washington, D.C., where they'll get to visit the International Spy Museum. But it seems as if someone is spying on them—or at least leaving coded messages that even the Code Busters can't crack. And once they arrive at the museum, they notice they're being followed by a mysterious stranger. Then a classmate goes missing. Could the unknown spy be responsible? It's up to the Code Busters to find out! Can you crack the code? Test your brain with the Code Busters to see if you have the right stuff to be an ace detective. Answers are in the back, if you ever get stuck.

The Code Busters are excited for their class field trip to Angel Island, known as the Ellis Island of the West. One of Mika's ancestors passed through the island's immigration station in the early twentieth century, and Mika thinks he may have left behind some secret messages . . . plus a very special box. But as the Code Busters search for hints from the past, they get caught up in an even bigger secret.Can you crack the code? Test your brain with the Code Busters to see if you have the right stuff to be an ace detective. Answers are in the back, in case you get stuck.