One day, Mac (smartest boy in his class in a small town in California) receives a telephone call from the Queen of England, recruiting him to find the crown jewels (well, actually just the Coronation Spoon) and so Mac embarks on his first adventure as a secret agent -- with the assurance that the Queen will give him a note excusing him from school.
Mac B, kid spy ; 
Crown jewels -- Great Britain -- Juvenile fiction.
Spies -- Fiction.
Stealing -- Fiction.
Theft -- Juvenile fiction.
Undercover operations -- Fiction.
Undercover operations -- Juvenile fiction.