Mystra is murdered by Cyric with the help of Shar. This event causes the weave to collapse and causes the Spellplague (lasting until 1395). Mystra’s death results in a release of chaotic raw magic defiled by the Far Realm, the very nature of arcane magic changes, and Toril transforms as it melds and exchanges parts with the sister-world of Abeir. Cyric is punished by being bound to his throne for one thousand years. Mezro, in Chult, appears to be destroyed by the Spellplage as its Barae protectors pull it into a demiplane to save it (and also to save it from Ras Nsi, saying it will not return until Ras Nsi is dead).