I visit the Oghma Preist and he says nothin g what gives?

if you lost a party member at the enterance to the graveyard district and bohdi turned them into a vampire, you take the body of party member and bohdi's heart to temple ruins (umar hills quest). place body and heart on statue beyond the letter puzzle on the floor (that spells out amaunator). this should bring party member back. this process is detailed in one of the books you obtained.