Suspecting that Cary and his Mischief Knights are behind recent school vandalism pranks, Kristy and the Baby-sitters begin an investigation that challenges them to solve eight puzzles in order to catch the real culprits.

Suspecting that Cary and his Mischief Knights are behind recent school vandalism pranks, Kristy and her friends begin an investigation that challenges them to solve eight puzzles in order to catch the real culprit.

Accompanying young child star Derek Masters aboard the "mystery train" that is publicizing his newest movie, Kristy, Abby, and Stacey fend off a saboteur who is staging dangerous accidents. Original.

Accompanying young child star Derek Masters aboard the "mystery train" that is publicizing his newest movie, Kristy, Abby, and Stacey fend off a saboteur who is staging dangerous accidents.

Learning that a local girl who was humiliated at a prior event is trying to sabotage the Stoneybrook Middle School Mischief Night Dance, the baby-sitters hope to stop the girl and set things right.