Your search for Addie's missing sons found the remains of Amlach Wheatley clutching his brother's journal. The last cryptic entries seem to reveal that Amlach heard fell voices coming from the southern reaches of the Barrow-downs.
'The tidings you have brought grieve me deeply, for Amlach was young and strong, and I loved him dearly. The only consolation in my grief is that he died in search of his brother whom he loved more than his fear of that dreadful place.
'If this journal is true, then Amlach still believed there was hope for his brother, though my heart fears the worst.
'Please, ${PLAYER}, search out the barrow over the mire where Amlach heard his brother, bring my son back safe to me.'
The journal you found seemed to indicate that Malin was taken to the southern Barrow-downs to a barrow overlooking an evil mire.
Addie Wheatley has asked you to search for her other son, Malin.
Addie Wheatley awaits your return at the relative safety offered by her guides at the Dead Man's Perch.
In your search of the Barrow-downs, you found both of Addie's sons, Amlach and Malin, but far too late to be of any help to either. The foul creatures of the Barrow-downs had killed them both and took Malin's remains for their own. You should return to Addie Wheatley and tell her what has happened to her son.