If there's one thing Polly McDoodle doesn't like, it's change. But things are changing all around her: her brother has moved to Regina to play hockey; the treehouse headquarters of the Clay/McDoodle Detective Agency got wiped out in a summer storm; her mentor and friend Isabel has headed for an artist colony in Mexico; her friend Erin has moved to Winnipeg; she's starting a new school; and -- the icing on the cake -- the homeroom teacher she was finally...