[Ubyvstvo v Londoni]

Larry and Agatha were preparing for Christmas Eve when cousin Darren appeared on the doorstep of the Mystery House. He asks the young detectives to help investigate a case handled by their ancestor Leonard Mystery. This is how Agatha and Larry's new adventure begins. They will visit the family crypt in Highgate Cemetery, go down a tunnel to an underground river and even end up in Buckingham Palace! The hunt for evidence becomes more and more interesting with each passing hour!.