|This article is about the barrier between dimensions. For other uses, see Hellmouth.|
Hellmouth referred to a sort of portal between Earth and the next dimension. For this reason, the Hellmouth's area was a hot spot for supernatural activity, sending out mystical energy that affected the nearby population, and attracting supernatural creatures even when closed.
Distortions of the laws of physics were made possible by the Hellmouth's influence, including Billy Palmer's nightmares intruding into reality and the ignored Marcie Ross becoming invisible, as well as the presence of notable monsters, such as the Master, the She-Mantis, Moloch the Corruptor, Machida, Ovu Mobani, and Balthazar. A Suvolte demon also went to Sunnydale with the intent on breeding.
According to Willow Rosenberg, the Hellmouth was responsible for the many churches located in Sunnydale as it made people "pray harder". Spike took a severely weak and injured Drusilla to the Sunnydale Hellmouth in hopes that its energy would restore her to full strength. It was credited for the hysteria that gripped Sunnydale following the First Evil's uprising, causing most of the population to flee and the Sunnydale police to resort to vigilante actions.
Opening a Hellmouth posed apocalyptic threats predicted by portents, allowing demons to cross over to Earth. One such demon included a tentacled beast with multiple heads and Turok-Hans.
The Sunnydale Hellmouth laid underneath the library of Sunnydale High School, under the principal's office in its rebuilding. The Seal of Danzalthar was the gateway, located in the school's basement. Buffy Summers, the last guardian of this Hellmouth, identified that its activity usually got apocalyptic proportions around May.
There were attempts to open the Hellmouth by the Master in 1997, the Sisterhood of Jhe in 1999, and a Sacrifice of Three performed by three Vahrall demons in 2000. It was effectively opened by the First Evil in 2002, Lissa in 2003, then by Buffy, Faith, and a group of Potential Slayers again in 2003.
Spike used a magical amulet to destroy the First's Turok-Han army (as well as himself) and close the Hellmouth. The ensuing cataclysm not only collapsed the Hellmouth, but swallowed the entire town of Sunnydale along with it. As of spring 2003, the Sunnydale Hellmouth was permanently closed and inactive.
After the Sunnydale Hellmouth had been destroyed, Rupert Giles mentioned Cleveland being known for having one as well. For some time, it was guarded by a Slayer Organization squad led by Robin Wood and assisted by Faith Lehane.
During the period of end of magic, the courtesan demon Morgan used a shard of the destroyed Seed of Wonder to perform a ritual and open the Hellmouth located on Easter Island, Chile. Her attempt, though, was interrupted by Spike, who was then attacked by the Moai creatures guarding the place.
Behind the scenes
- The non-canon novel Dark Congress reveals the existence of a Hellmouth in Providence, Rhode Island, while the dubious canon novel Slayer features the creation and closing of a small Hellmouth in Dublin, Ireland.
- The non-canon miniseries Spike: The Devil You Know has the vampire Tansy Fry opening an artificial miniature Hellmouth beneath Los Angeles, but it is destroyed.