The Unwise Young, They Say Do Ne'er Live Long (5E)

From publisher blurb: A 5th Edition Mini-Dungeon adventure for 4-6 PCs of levels 12-13 Uskonto the Unshakeable, still a relatively young man, disappeared after taking responsibility for a child’s death when charging in to save a village. Rumor suggests he’s in Underworld, seeking atonement, but he’s needed! Perhaps allies can help the PCs, while foes will certainly hinder them...