(From the publisher):
Mr. Hollister has to buy a boat for a customer at the home of the Sunshine Circus in Florida, Circus Island. Pam enters Zip in a dog show in which he gets hurt and two poodles are stolen. The thief's activities are far more sinister than anyone had at first imagined. So they probe the mystery and the boys learn a tumbling act, Holly tries her skill at tightrope walking, and they all find that a clown's smile is sometimes only a happy mask that hides sorrow.
Original title: The Happy Hollisters at Circus Island
Genre: Fiction→ Children & Young Adult→ Mystery