Carter Lewis is thrilled when he gets a coded message from his computer-programming uncle offering him the coolest job in the world - helping test a new virtual reality program. Carter will even put up with Uncle Dan's other new helper, Carter's brainiac cousin Isabelle. Everything is fantastic until Uncle Dan discovers someone has tampered with the code in The Three Musketeers. The hacker has left clues to his identity, so Uncle Dan sends the kids...