When Digit's systems go wonky, Motherboard sends him to the caves that house the Synchronizer, the beautiful crystal that keeps all borgs correctly timed. But before he can be put back in sync, he gets a glitch and tosses his crystal synchrometer into a tunnel and then flies off the wrong way down into a deep, dark chasm. Called in to help, Jackie, Matt and Inez meet Jules, the cave's timid guard, who teams up with them to find the synchrometer (using the unique geometry of crystals) and to find Digit, who's hopelessly lost. To thwart their plans, Hacker steals the Synchronizer. Can the kids figure out how to replace it and save their friend?