Coated in Blood

Living in Understone Keep, Moth gro-Bagol asks the Dragonborn to obtain a Daedra Heart for him.

Walkthrough
Moth asks the Dragonborn to obtain Daedra Heart for him. These can be obtained from the Daedra at the Shrine of Mehrunes Dagon, bought from Enthir at the College of Winterhold or bought from Babette. For all locations to obtain a heart, see here.

When the heart has been obtained and brought back to Moth, he'll reward the Dragonborn with a random piece of leveled armor.