|Season 1, Episode 2|
|Air date||January 22, 2002|
|Written by|| Dan Elish
George Arthur Bloom
|Directed by||Larry Jacobs|
"Lost My Marbles"
Dr. Marbles is captured by Hacker and taken to Castleblanca, a Cyberspace version of Transylvania. Hacker’s goal: transfer Marbles’ brain power into his newly built robot named Megabyte! Summoned by Motherboard, the kids and Digit arrive with the knowledge that Hacker has taken Marbles to a castle, but which one? There are hundreds and hundreds of castles. To find Marbles, the kids must master the art of properly collecting data, organizing it and graphing the results — results that are sometimes surprising!
- As the Cybersquad are talking to Motherboard towards the beginning of the episode, Inez and Jackie's voices are swapped.
- Main article: Castleblanca (transcript)