This quest is not available in game.
Use the portal in Grommash Hold to return to Stormwind Keep and deliver Thrall's message to King Varian Wrynn.
Your champion, Bolvar, died in defense of our world. The Horde is saddened by the loss of such a great hero, but the Horde was not responsible for the cowardly attacks made by Putress at the Wrath Gate. We have also lost mighty heroes because of this betrayal.
Tell your king that we will do everything in our power to bring the perpetrators of this cowardly act to justice. We will do all that we can to avoid conflict with the Alliance, but we will not hesitate to defend ourselves if provoked.