Age of Birthday Boy: 6 years old
Age Range of Guests: 3-9 years old
Gender of Guests: boys and girls
Potential Age Range of Theme: 3-12 years, depending on specific focus & activities
This party was inspired by the "Jigsaw Jones" chapter book series by James Preller which our son loved at the time. But, it could easily be adapted for any detective-themed party.
Invitations: We cut out puzzle shapes and glued them on the outside of the invitations. Small stickers taped the card shut for a more "secretive" feel.
The Cake: Using a 9x13 inch cake we cut it into a puzzle shape using a template made from wax paper. This was decorated simply using frosting & sprinkles with a simple math problem on it that indicated how old our son was turning. Cupcakes were decorated with a number code and the kids had to figure out that it read "Happy Birthday".
Games & Goodies: The front door read "Welcome to the Jigsaw Jones Detective Agency", each child was given a detective badge as they arrived, and they put their fingerprints on them using washable ink. We played a number of scavenger-hunt and code-breaking games, as well as games to test their memory. The kids had to follow clues, crack the codes (number codes, alphabet codes, riddles, and symbol codes), and find missing puzzle pieces.

There were then two puzzles to put together once all the parts were located - one for younger kids and one for the older crowd. For a memory game the kids were briefly shown a group of random household items, the items were hidden, and they had to remember as many as possible. The first turn gave the kids plenty of time to see & remember the items. By the last try the items were viewed only briefly and they all did a great job figuring out how to work together to get them all right.
Goodie bags included detective notepads & pencils, puzzle piece erasers, their name badges, and a variety of candy treats.