This quest is not available in game.
Travel to Stratholme and slay Ramstein the Gorger. Take his head as a souvenir for Nathanos.
I was overwhelmed. On this very stead, I stood... held my ground in defense of Lordaeron. The farm and all on it were waylaid by a gigantic wave of Scourge.
The wretch. The filth. It hovered above me, entrails hanging from its gaping chest cavity.
I woke as Scourge. For so long I was helpless. My mind had coalesced with the Lich King's.
She came for me... somewhere, somehow, I knew she would. Free.
And now, I must have my vengeance - my vengeance on that which took from me my life. Destroy it.