The Temple of Mystra was a false temple in the town of Wheloon in Cormyr. Constructed in 1374 DR on the ruins of an old citadel on the edge of town, it was dedicated to Mystra, goddess of magic, but was in fact a front for worshipers of Shar, goddess of shadows, and Cyric, god of lies. Under the guise of a holy ritual, they kidnapped, murdered, and sacrificed true followers of Mystra, wielders of magic, and ordinary people who'd become caught up in the snare. This was all part of a plot by Esvele Graycastle and the black dragon Despayr to rend a hole in the Weave of magic. The nefarious scheme was unveiled and thwarted by adventurers in service to Mystra.