【Esther Moser】

Dune: Prophecythrows a lot of new Dunelore at us,Esther Moser from the Butlerian Jihad fought against thinking machines to the beginnings of the Sisterhood that will one day become the Bene Gesserit.

However, one of the biggest new terms we learn in the first episode is "Tiran-Arafel," a word uttered by Mother Superior Raquella Berto-Anirul (Cathy Tyson) on her deathbed. The warning accompanies a vision of the Sisterhood's destruction, suggesting that whatever Tiran-Arafel is, it's nothing good.

Dune: Prophecy confirms this in the very next scene, when young Sister Valya Harkonnen (Jessica Barden) informs her fellow Sisters of Raquella's words. Her compatriot, Sister Kasha (Yerin Ha) gives the exact definition. "A reckoning," she says. "A holy judgment brought on by a tyrant."

However, the idea of Tiran-Arafel, or more specifically, just arafel, is not unique to Dune: Prophecy. Instead, arafel — which is Hebrew for "fog" — pops up at the end of God Emperor of Dune, the fourth novel in Frank Herbert's series.

As (spoiler) Paul Atreides's son Leto II (who is also a sandworm-human hybrid) dies, his last words are, "Do not fear the Ixians. They can make the machines, but they no longer can make arafel. I know. I was there."

There's a ton to unpack there, from the machine-creating Ixian civilization to Leto's visions. (Like father, like son.) But the main takeaway from God Emperor of Dunefor the sake of Dune: Prophecy is that arafel is later described as a "cloud-darkness of holy judgment." Essentially, it's the apocalypse for humankind.

Dune: Prophecy adjusts that meaning a little bit, with the "tiran" addition emphasizing that the Sisterhood's judgment will specifically be brought on by a tyrant. But who could that be?

• Space babies and time jumps: How 'Dune: Part Two' handles the challenge of Alia Atreides
• 'Dune: Part Two' ending explained: What comes next for Paul and Chani?
• Denis Villeneuve breaks down the evolution of sandworms in 'Dune: Part Two'
• Fan who has seen 'Dune: Part Two' 10 times breaks his silence
• How to watch 'Dune: Part Two' at home: Where is it streaming?

As of now, all signs point to soldier Desmond Hart (Travis Fimmel), who seems to have it out for the Sisterhood. After all, his mysterious ability to burn people without even touching them seems like exactly the kind of power a tyrant would have.

New episodes of Dune: Prophecy premiere Sundays at 9 p.m. ET on HBO and Max.

(Editor: {typename type="name"/})