When the Thea Sisters compete in a battle of the bands, in hopes of meeting their favorite band Top Direction, they must find their sound, write a song, and identify the saboteur who is trying to ruin their performance.
Joe and Frank abruptly break up to tackle their latest case- a series of near-fatal accidents involving teenagers who dress up as zombies- after a heated argument about how to investigate the cause of the crimes.
Frank and Joe Hardy go undercover on a reality TV show to find out why a contestant has mysteriously died, but the strain of working together may drive them apart before the mystery can be solved.
Joining Squiggle at school, Johnny Boo discovers there is so much to learn, and after solving the mystery of "two plus two," he and Squiggle try to figure out how the Mean Little Boy got bigger--and grew a mustache!