Cardiff Space-Time Rift

The Cardiff rift is a time rift situated in (and above) Cardiff.

History

The Rift has existed for an unknown length of time.

The Rift and Abaddon

The Rift, in some manner, acted as a prison for Abaddon. However, unlike The Beast, Abaddon could easily be freed if his particular trap was opened. (TW: End of Days)

The Disciples of the Light may possibly have created it, and likewise the rift itself.

Gelth use of the Rift

The rift was known to the Gelth in 1869. The Gelth had used the Rift to try and take over the bodies of Human corpses and then eventually attempt to invade the planet and kill the entire species. During this attempt, the rift was closed by a psychic named Gwyneth . (DW: The Unquiet Dead)

Torchwood's interest in the Rift

At an unknown time, although evidently between 1879 (DW: Tooth and Claw) and the 1950s .Torchwood found themselves unable to effectively get through the Rift themselves, but found themselves interested in monitoring it and securing whatever useful items might pass through it into Cardiff. (torchwood.org.uk)

The Widening of the Rift

The Rift was later used in September 2006 by both the the Doctor (to power up the TARDIS) and by Blon Fel-Fotch. Blon Fel-Fotch, now mayor of Cardiff, built a nuclear power station on the site of the rift and plotted to cause a core meltdown. The meltdown would destroy the Earth, generating a shockwave that she could ride to escape off into space using a tribophysical waveform macro-kinetic extrapolator. The extrapolator, connected to the Doctor's TARDIS, accidentally widened the Rift and caused an event known as the Cardiff earthquake. (DW: Boom Town) Since that event, the width and activity of the Rift has increased. (torchwood.org.uk)

Torchwood 3 and the Hub

The interaction between the TARDIS and the Rift had created a perception filter at the place where the TARDIS had landed in Cardiff earlier. This made for a hiding place for a lift going from the suface to the underground. (TW: Everything Changes)

At an unknown time, the Torchwood Institute set up a Welsh branch, Torchwood 3.

Presumbably, this occured before the Cardiff earthquake and possibly as a response to it.

Located in an underground base called the Hub and under the command of Captain Jack Harkness, Torchwood 3, had the task of monitoring the Rift and phenomena associated with it and with securing for Tochwood any artifacts that might come through. (TW: Everything Changes onwards) The Hub also possessed a Rift manipulator (TW: Captain Jack Harkness, TW: End of Days).

The fracturing of the Rift

Events engineered by Bilis Manger (TW: Captain Jack Harkness, End of Days) contrived to trick Torchwood 3's Owen Harper into using the Rift manipulator to widen the Rift on purpose (TW: Captain Jack Harkness). This caused the Rift to fracture, causing time slips worldwide and to cause more of the alien Weevils, a Torchwood and sufferers of bubonic plague, to appear in Cardiff . Finally, as Manger had planned, the Rift opened up wide enough to release Abaddon. (TW: End of Days)

Jack stated that the area would become more active after the opening of the rift and the death of Abaddon. (TW: End of Days)

Use by other extraterrestrials

Humanoids known as Weevils, have used the Rift to cross over into Cardiff for unknown reasons of their own, more so as the Rift de-stabilized. (TW: Everything Changes, Combat, End of Days)

Other aliens, such as Mary and her guard in 1812 (TW: Greeks Bearing Gifts) and the "Sex Gas" (DW: Day One) circa 2007, perhaps coincidentally, came to Earth close to the Rift, though apparently neither used it as their means of transport onto the planet.

Indirect influence upon Cardiffe

In with common with time fissures (DW: Image of the Fendahl), growing up near the rift tends to enable one to develop psychic powers, as with Gwyneth, who had the gift of clairovoyance (DW: The Unquiet Dead]).

This may also account for the abilities possessed by Bilis Manger.

Some individuals, such as Sean "Bernie" Harries, locally, have engaged in the selling of alien "flotsam and jetsam" that has passed through the Rift. (TW: Ghost Machine') Another human, Lynch Frost, started an underground "fight club" of sorts where humans could go up against Weevils, for a fee. (TW: Combat)

• Official in-universe Torchwood file on the Cardiff Rift