Fenric

Fenric a.k.a. Hastur the Unspeakable or ka Aboo Fenran was an immensely powerful sentient force, at least as old as the universe itself and an intelligence of pure evil.

Origins
The being later known as Fenric was one of two forces, one good, one evil, which were present at the Dawn of Time. (DW: The Curse of Fenric)


 * The fate of the good force, if personified, remains unknown.

Some sources state that Fenric originated not in the beginnings of this universe but, like the other Old Ones, in a universe before this one. These accounts state that Fenric bore (and still bears) the name of Hastur the Unspeakable (NA: All-Consuming Fire). The name Fenric came from a mythic figure in Norse mythology. The myths described a monstrous wolf which would, during the final battle between gods and beasts, destroy the world at the end of time. (DW: The Curse of Fenric).

Entrapment of Fenric
The Doctor's first known encounter with Fenric was in Constantinople in the middle of the 3rd century AD, when the Time Lord challenged the entity to a game of chess, knowing that the metaphorical struggle would weaken Fenric. The ploy worked and the Doctor was able to trap Fenric in a flask and banish him to the Shadow Dimensions. (DW: The Curse of Fenric)

Fenric's stratagem
Yet Fenric's power was such that his influence still continued to pervade space and time, and he began setting into motion the events that would ensure his escape.

Fenric summoned the Ancient One, the last Haemovore, from the future. When Vikings stole the flask containing Fenric sometime after the 10th century, the Haemovore followed them and the flask to Northumbria and Maiden's Point. Fearing its evil influence, the Vikings buried the flask beneath St. Jude's Church, leaving a runic inscription warning that the flask was cursed. The Haemovore remained beneath the waters of Maiden's Bay, gradually recruiting new members. The Haemovores, also known as the Wolves of Fernic, awaited their master's release. (DW: The Curse of Fenric)

Though still imprisoned Fenric continued to manipulate the timelines in ways that would ensure his release. As she conducted a black magic ritual, Fenric used a time storm to whisk Lady Peinforte from her native time period of 1638 to 1988 to retrieve the Nemesis statue. (DW: Silver Nemesis) He also transported Ace to Iceworld by time storm so that she could meet the Doctor and joined him on his travels. (DW: Dragonfire) As Ace bore the "curse", Fenric hoped that he could use Ace as a weapon against the Doctor. (DW: The Curse of Fenric)


 * The curse enabled Fenric to control the destinies of certain people in an unspecified way, so that they would make certain choices without knowing that these choices played into Fenric's plan. By implication, Fenric could only take over the bodies of people sharing in the curse.

At some point during his imprisonment Fenric played chess with the Celestial Toymaker, with the loser to become the slave of the winner. Fenric initially got the better of his opponent but was thwarted when the Toymaker played for a stalemate. (DWM: Games)

Escape and defeat
In 1943, Maiden's Point served as a the location of a military base housing the ULTIMA machine, an early computer designed to decipher German code. The ULTIMA machine also had the secret purpose of translating the runic descriptions and so freeing Fenric. Once released, he occupied the body of Doctor Judson and had the Haemovores, already killing every Human they could find, summon the Ancient One from his dormant state. Fenric later possessed Soviet Captain Sorin.


 * All or most of the people at Maiden's Point at that time, including at some of the Soviets, had the taint of Fenric's curse.

The Doctor attempted to trap Fenric once again using a game of chess, as before, but having taken over Sorin's body, Fenric had learned the solution to the chess puzzle. Fenric was finally defeated when the Ancient One turned on him, destroying Sorin's body and leaving Fenric without a corporeal host. (DW: The Curse of Fenric)

Other information
At some stage of Fenric's existence, it briefly met and played a game of chess with the Celestial Toymaker. (DWM: Games)

Behind the Scenes
Characters called the Gods of Ragnarok had appeared in The Greatest Show in the Galaxy, a story from the previous season of Doctor Who. Because they did not wish to confuse the public by having the same name appear in two different contexts, the production team forbade Ian Briggs, the writer of The Curse of Fenric from using the name Ragnarok, to describe the apocalyptic time prophesied by Norse mythology when Fenris Wolf would rise up and eat Odin, the father of the gods. The writer also used the name Fenric for the great wolf, rather than the usual name.