Akaban's Temporal Temple

From publisher blurb: Mini-Dungeon for 4-5 characters of levels 9-10 Akaban, a drifter from an ancient civilization bouncing across time and space, doesn’t have long left and must find adventurers capable of stopping possibly the greatest threat to this timeline. Himself. He is only able to provide a cryptic explanation of the danger and a pendant which perpetually points in the direction of an ancient temple before a temporal rift appears and swallows him.