The final age of Netheril began with the birth of the powerful mage Karsus in −696 DR, whose later actions led to the empire’s collapse. A spellcasting prodigy, Karsus created the enclave of Eileanar and discovered heavy magic. Key events during this era greatly destabilized Netheril and northern Faerûn. In −681 DR, arcanists known as the Night Parade visited the Demiplane of Nightmares.
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Later, in −553 DR, the Plane of Shadow was discovered, where Telamont Tanthul would eventually relocate his enclave. Meanwhile, the subterranean phaerimm, harmed by Netherese magic, launched a devastating war in −461 DR, draining life and magic from Toril and the flying enclaves. This resulted in wastelands, wild magic zones, and mass evacuations. Many arcanists fled to Illusk, the Tower of the Star, and the Northdark. Civil unrest followed as commoners also fled Low Netheril. In −345 DR, the Terraseer Arthindol warned that the goddess Mystryl would soon act against Netheril in an unprecedented way.
Mystra’s death caused the Weave—and by extension the Shadow Weave—to collapse, disrupting arcane magic across Faerûn. Cyric's madness corrupted the remnants of magic into destructive blue flames, initiating the Spellplague.
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This phenomenon warped reality, mutating creatures into plaguechanged beings or leaving survivors with magical spellscars. The Spellplague first appeared in Toril as a storm in the Mhair Jungles, devastating Halruaa, though some of its people escaped by shifting to Abeir. Massive magical upheaval followed, warping regions like Sespech and creating the Plaguewrought Lands. Portals and gates spread the plague across Toril and beyond, killing or maddening thousands of spellcasters. In 1386 DR, the Spellplague reached Abeir, causing parts of Abeir and Toril to swap places. This cataclysm destroyed the Primordial fortress Glaur and reshaped Laerakond, affecting dragonborn lands like Tymanchebar. Parts of Unther were mistakenly believed destroyed but were actually transported to Abeir. Laerakond ended up on Toril as "Returned Abeir," while Maztica was shifted to Abeir.
As the Second Sundering unfolded, stars fell, dead gods returned, and divine conflicts erupted across Faerûn. Earthquakes and volcanoes marked the re-separation of Abeir and Toril, restoring many lands lost during the Spellplague. ...Realms like Halruaa and Evermeet returned, and long-missing ships reappeared. Key events included the separation of Asmodeus and Azuth, the rise of Nanna-Sin as a dragon turtle, and the victory of the dragonborn over the Untherites. Mulhorand also successfully rebelled against High Imaskar, abolishing slavery. Larloch plotted to become a god of magic, while Telamont Tanthul sought to create a new Shadow Weave by draining ancient magical sites. Elminster and Mystra’s Chosen raced to restore the Weave, clashing with factions like the Red Wizards and the Netherese in Candlekeep. In Myth Drannor, a massive battle erupted between the Chosen, Larloch, and the Netherese. Dove Falconhand and the Srinshee made heroic sacrifices, and Elminster defeated Tanthul. The Netherese enclave Thultanthar crashed, but the Tree of Souls and part of the city were saved by baelnorns. By the end of 1487 DR, Mystra was fully restored, the Weave stabilized, Abeir and Toril were finally separated, and the Second Sundering came to a close.
In Waterdeep, the legend of the Neverember treasure lured many, including a unique group of adventurers. Ghilan'naïn, a druid from another world raised in the city, sought a way home; Gheorghievich, a lost leonin of royal blood, looked for guidance; and Ember, an assassin fleeing a cult, sought riches and freedom. ...Their journey began with a mission to cleanse an old building, where they met the specter Lif, who offered them a home in exchange for restoring his tavern. Their quest led to uncovering plots involving Jarlaxle, a drow seeking the treasure to free his people from Lolth’s grip. After an attack in the city, they met key figures like Valetta, a draconic cleric, and the living construct Nim. They also earned the favor of Silverhand and her council, who confirmed the reward for the treasure's discovery. At a noble's party, they saved a hostage and retrieved the Golorr Stone, which led them to the treasure chamber. After defeating Jarlaxle, they used the three keys to enter the chamber guarded by a dragon in disguise. Granted access, they received their rewards—Ghilan'naïn choosing a teleportation staff. The group attempted to follow her back to her world, but something went wrong. The unstable portal sent them... somewhere else entirely.
After stepping through the unstable portal, the group was split: Gheorghievich landed in Ghilan'nain's war-torn homeland, while the rest crashed into a mysterious forest near Waterdeep. Unconscious from the fall, they were discovered by Catryna, a succubus masquerading as an adventurer. ... Under orders from the Sovereign of the Twilight Court, she attempted to siphon Ghilan'nain's magic, but the druid awoke just in time. Pretending to be an ally, Catryna healed the group and offered to guide them—still intent on stealing the remaining power. As they departed the forest, enchanted walking bushes stole key magical items, forcing the group to pursue. Their chase led to Kavnu, an eccentric kobold inventor, who joined them after a brief misunderstanding. Together they discovered a hidden village cloaked in magical concealment, its people emotionless and trapped within a dome. Inside they met Daphne, a barmaid and unwilling member of the Twilight cult, along with her companion Cosmos, another succubus. The group investigated a massive underground dungeon beneath the town, uncovering secrets level by level—rogues, goblins, and ancient wards. Eventually, they found an Eluvian and used it to reach the top floor, where the mad wizard who ruled the dungeon resided. In battle, he trapped them in magical illusions of past traumas. When they awoke, they found Kavnu gravely wounded, having defended them alone. In a final clash, the wizard attempted to destroy the dungeon, but the group escaped. With the magical dome finally broken, they began their return to Waterdeep to seek Silverhand’s guidance—Catryna still by their side, her hidden motives intact.