Taking a turn caring for the class pet hamster, Marion is devastated when the hamster goes missing and she receives an anonymous letter in her locker with clues leading to a mysterious scavenger hunt.

Includes excerpt from Critter Club book #17, Amy on park patrol.

Machine generated contents note: ch. 1 A Secret Surprise -- ch. 2 The New Classmate! -- ch. 3 Marion Puzzles It Out -- ch. 4 A Very Close Call -- ch. 5 Teddy's on a Roll -- ch. 6 Hamster Hunt -- ch. 7 Two Mysterious Clues -- ch. 8 Unexpected Treasure -- ch. 9 The Principal's Office -- ch. 10 Teddy's return.