It's the Ultimate Challenge: the most difficult riddles combined with the most incredible photographs—culled from the original I Spy books—to create the most intriguing I Spy book ever!

Think you know every I Spy book out there? Think you've found every last bauble, bow, striped cat, and cloudy ship?

Think again!

Jean Marzollo has written her most challenging riddles yet to accompany Walter Wick's fabulous photographs culled from the original I Spy books.

You've never seen I Spy like this!