The Stranger (Colin Baker) arrives on Earth with no memory of who he is or why he's there. However, two men on a secret mission seem to know his identity and the owner of a local bar/club seems to be hiding a secret in an upstairs room. Unsure of whom to trust or even believe, The Stranger must try and unravel the threads of his mysterious past...a past he may not want to remember.

A henchman of Satan poses as a priest in order to get closer to young virgins he needs for human sacrifice.

维基：

This season introduced K9 to the series and saw the departure of Leela. It was originally intended to include Terrance Dicks' story The Vampire Mutations but, due to a major BBC production of Dracula, it was postponed. It later became Season 18's State of Decay. To replace it, Dicks quickly scripted the season opener, Horror of Fang Rock. The season took a two week transmission break over the 1977 Christmas period, between the broadcast of part four of The Sun Makers and part one of Underworld.

Doctor Liz Shaw, one-time companion of the Doctor at UNIT, is called upon to head a small team, P.R.O.B.E., to investigate strange happenings throughout the country. When she is called in to find the truth about the brutal murder of a retired headmaster she finds evidence of satanic rites near the murder scene. She soon discovers a web of deceit and corruption that extends back in time, threatening the current occupants of nearby Winterborne School. With P.R.O.B.E. under threat from within and the death toll mounting, Liz finds herself under increasing pressure from all sides to produce results… The Devil of Winterborne is at large and only Liz can stop it! Described as a British 'X-Files', this independent spin-off of 'Doctor Who' uses characters and actors associated with the classic BBC science fiction drama.

The Devil of Winterborne has only recently been exorcised by P.R.O.B.E. but when the body of it's last victim goes missing and a black magic grimoire goes missing from a local museum, Liz Shaw begins to wonder if the ghosts of the past have actually been laid to rest. As she revisits Winterborne School, Liz becomes convinced that the festering evil is once again attempting to exert it's influence. Liz is forced into an uneasy alliance with the now disgraced former headmaster of the school, Gavin Purcell as she must overcome her own emotions to fight the ancient evil that haunts Winterborne.

故事开始于图书馆，当John发现了Garrett先生的一条希伯来文的模糊求救信息，这场恐怖之旅正式开始——由Mark Gatiss导演的惊悚片《Tractate Middoth》，由Sherlock的Una Stubbs，Dr Who的Louise Jameson，Being Human的Sacha Dhawan等主演，让2013年的圣诞新年季欢乐与恐怖并存。它将在圣诞之夜播出。