In the fourth book of the Capital Mysteries—an early chapter book mystery series featuring fun facts and famous sites from Washington, D.C.—KC's mom is getting married...to the President of the United States! KC wants the day to be perfect, but someone keeps leaking wedding secrets. They newspapers have even printed where the president and his bride are going on their honeymoon. To save the wedding, KC and Marshall have to track down the spy in the White House!