Equinox is a short adventure for four 7th-level characters. The party may consist of any mix of classes. The adventure should prove a reasonable challenge for characters from 6th to 8th level and can be set in any campaign world.
There are fleeting places in this world, places that are no more lasting than a shadow. Legend holds that the most fleeting among those eldritch places is a building that exists for only 12 hours on two days of the year: the spring and fall equinoxes. Reports about what the building contains vary greatly: Some say it’s a monastery; others, a library; still others are convinced it’s a temple. But all these different reports agree on one item: On the equinox, the building appears on a high hill when the first rays of dawn strike the tip of a tall white tower (twin to a black tower opposite it), and it disappears the same day at sunset when the last light leaves the twin black tower.