Seal of Danthalzar

The Seal of Danthalzar is a fictional device from the American television series Buffy the Vampire Slayer. The Seal resembles a fairly stereotypical demonic symbol, featuring an inverted pentagram and a goat's head. The Seal is seen in Season 7 of the series, in the episode Conversations With Dead People. It is located over the Hellmouth in the basement of the rebuilt Sunnydale High School. Andrew Wells is seduced by The First Evil in the form of Andrew's dead friend Warren Mears into opening the Seal. The Seal can only be opened by a blood sacrifice, so Andrew brutally murders his friend Jonathan Levinson who, because he is anemic, doesn't have enough blood to open the Seal. Jonathan's body and the Seal are found by Principal Robin Wood and buried.

The First Evil sends its minions, The Bringers, to capture Spike. They bind him over the Seal and bleed him. The Seal opens sufficiently to allow one Turok-Han (a.k.a. "Ubervamp") to slip through. The first Turok-Han is killed shortly thereafter by Buffy.

Lissa, a minor demon, tries to open the Seal using the blood of Xander Harris but is unsuccessful.

In the episode Storyteller, the Seal is wreaking havoc on the Sunnydale student body, inspiring fighting, spontaneous combustion and students turning invisible. Five students perform a ritual over the Seal which causes it to emit white light. The students are transformed into Bringers. Buffy, stating that Andrew May Be able to communicate with the Seal, takes him to it. Actually, Buffy and Willow have deduced that while blood opens the Seal, tears of remorse close it. Buffy forces Andrew to face up to his actions in murdering Jonathan and his tears fall upon the Seal, closing it and temporarily stopping its deliterious effects.

In the series finale, Chosen, Buffy, Faith and several Potential Slayers cut their hands and bleed on the Seal, opening it. They enter the Hellmouth itself and engage the forces of The First Evil on its own ground. After a pitched battle, an amulet worn by Spike begins to glow. A beam of sunlight shines down into the Hellmouth, focused and amplified by the amulet. The forces of The First Evil are destroyed, the Seal and the Hellmouth are sealed and the entire town of Sunnydale is consumed in the destruction.