The case of the green guinea pig (jack gets a clue #3)

Another funny mystery from bestselling author Nancy Krulik!Our big school trip was at the end of the week, and I couldn't wait! But someone kept playing pranks at school, including dyeing the class guinea pig green. I love a good practical joke, but Principal Bumble threatened to cancel the trip if the pranks didn't stop. I knew what I had to do--talk to the animals around school to get some clues. That's right--I can talk to animals. It sounds crazy, but it's true. Now it was up to me and my brainiac friend Elizabeth to solve this mystery in time to save our trip!