Return to the Searing Gorge and find Dorius's archaeology unit.
There is an empty, vacuous hole, where my heart used to be, <name>. The loss of Dorius is not one that I will soon recover from. I must see his final wish through - the perpetrators of this cold blooded murder must be brought to justice.
Return to the Searing Gorge and fulfill his last request: Free his men. The Dark Iron dwarves force their slaves to work in a sweltering mine called the Slag Pits. Search there for Dorius' men.