Bring the Skull of Horgus and the Shattered Sword of Marduk to Carlin Redpath at Light's Hope Chapel.
The Annals of Darrowshire tells of the villains of that battle. It tells how the ghoul lord Horgus the Ravager was destroyed by Alliance forces during the battle. His body was cast into a lake, northwest of Corin's Crossing, and his skull remains there.
Marduk the Black was never defeated, but his fabled sword was shattered and lost. It lies at the bottom of the gorge west of Corin's Crossing.
Retrieve these items, [player]. I know not why, but I am certain their fate lies with you.