FAVORITE DESCRIPTIONS OF OCCULT RITUALS IN WEIRD LITERATURE?

[Gnosticangel]

I've just finished rereading Algernon Blackwood's "Smith: An Episode in a Lodging-House," and very much enjoyed the atmosphere of the Outer and the Uncanny evoked in the ritual that is the climax of the story. Blackwood's tale is in the public domain:

Smith: An Episode in a Lodging-House by Algernon Blackwood

The story has me thinking about other examples of magical rituals in literature, which generally seem to display both transgressive and eerie elements ("transgressive" because either practitioners cross natural boundaries between worlds that are not meant to be crossed, or because they commit actual crimes in the course of the ritual, such as dead body parts in a necromantic ceremony, or a sacrifice of a living being).

In some cases these rites represent the sole Weird dimension in otherwise heroic-type fantasy works, such as the Great Sending of King Gorice the XII in E.R. Eddison's "The Worm Ouroboros." (See Chapter IV, "Conjuring in the Iron Tower" in link below)

The Worm Ouroboros

I'm also an admirer of Aleister Crowley's occult satire, "The Moonchild," which contains another great example of magical, Weird ritual, seen in Chapter XV, "OF DR. VESQUIT AND HIS COMPANIONS, HOW THEY FARED IN THEIR WORK OF NECROMANCY." (Link below)

MOONCHILD - Chapter XV

Another classic example, this one purporting to be a true account, is Benvenuto Cellini's famed "Encounter with the Spirits:"

Benvenuto Cellinis Encounter with the Spirits | The Curio Cabinet

I love all the above stories. But for me, my favorite Weird magical ritual is in Clark Ashton Smith's "The Double Shadow," linked below thanks to The Eldritch Dark website:

The Double Shadow by Clark Ashton Smith

No doubt there are many other wonderful examples of occult rituals in Weird fiction. Can anyone recommend some?