Jon Preddle is a New Zealand-born author who has helped in the recovery of certain missing episodes. Preddle ran a fanzine in the 1980s which covered Doctor Who from the New Zealand perspective. He also appeared on the New Zealand version of television programme Mastermind with specialist subject Doctor Who. Preddle has subsequently been involved in the recovery of missing Hartnell and Troughton episodes from New Zealand (along with Paul Scoones). He has also written an unofficial guide to Doctor Who called Timelink. This does however include facts such as K'anpo Rimpoche from Planet of the Spiders being the same character as Azmael from The Twin Dilemma, and a "resolution" of the UNIT dating controversy which states that the stories must have been set in the early 1970s as the episodes themselves were made using early 1970s production techniques.