Ludo Farltrati was a dangerous criminal who bought the Doctor's TARDIS from brothers Ronnu and Briak Thanjess. When he couldn't get it to work, he beat up Briak and took Ronnu back to his warehouse. When the Tenth Doctor and Heather turned up and fixed the TARDIS, a short trip into the future led to him being arrested by the police, along with Ronnu. (COMIC: One Careful Owner)