Around the last and greatest of the primordial Everwood Trees, called Archaeus, the great sage River Runes began the construction of her library-citadel, the Arcane Helix, in 90 BE. She intended it as a center for all sorts of learning, an institute in which the secrets of the universe would be collected together. For long centuries before the great libraries of Canterlot and the Crystal Empire achieved preeminence, generations of scholars and magicians of all pony types studied and honed their craft under the fair boughs of the great Archaeus, supervised by the Loremasters of the Arcane Helix.

The last of these Loremasters was one Eldritch Lore. Alas, Eldritch did not accept the traditional caution that there were things ponies were not meant to know, and from her youth, she put the acquisition of knowledge before caution, friendship, and sanity. Eldritch and her minions scoured the barbarian world beyond the Equestrian pale, bringing back a near endless stream of scrolls and tomes to fill the libraries of the Helix, including stealing the Book of Horrors from Dream Castle in distant Ponyland. Her thirst for forbidden lore not quenched, Eldritch turned her prodigious magical talent to robbing the special collections of Equestria and the Crystal Empire. Delving deeply into the ancient manuscripts, Eldritch became increasingly isolated from her remaining allies, and the Helix attracted fewer scholars and students, rapidly gaining a negative reputation.

Eventually, in 704 AE, an incident in which four squamous horrors had plundered the Crystal Empire Secret Archives was traced back to Eldritch Lore. The Equestrian Royal Relief Corps prepared an expedition to arrest Eldritch, but she detected the expedition by scrying and inflicted heavy casualties on them as they approached the Helix, during which time most of her remaining associates fled. The RRC laid siege to the Helix, unable to penetrate its formidable defenses and beset by all manner of wicked sorcery. The royal archmage, Dusty Tomes, and his four companions - the pegasus Rouge Rogue, the unicorn healer Mercy, the earth pony archer True Strike, and the earth pony warrior Clever Cleaver - managed to infiltrate the Helix and confront Eldritch at the top of her citadel. The citadel disappeared from Equestria mysteriously shortly thereafter, and was not see again until 1833 AE when it appeared near Pebble.