What is Zack's special skill in the circus?
Who is Cubby in the story?
What kind of animal is Trouble?
Why is the circus at risk of shutting down?
Who becomes the main suspect in the theft at first?
How does Zack feel about being left in charge of the puppy?
What motivates Zack to solve the mystery?
Where does the story mostly take place?
How does Zack gather clues about the theft?
What does the story show about Zack by the end?