What would happen if someone decided to trick a whole town--by giving them toys? But not just any toys, you understand. Toys that had a powerful and sinister effect on their owners. And what if only two children knew the evil plot was in the works? The magic continues as John and Susan Kramar speed through this book of mystery and adventure. As the Fourth of July approaches, they know some scheme is brewing. Armed only with bicycles that possess wonderful powers, their job is to find out what the plan is and stop it.