Uh, do you mean Baine Bloodhoof and Garrosh Hellscream?
Anyway, haven't done that quest, but this is from Wowpedia:
Walk to the high tower in the middle and up to the top where Tal is. Talk to him to get a free ride to Orgrimmar.
Walk to the west where there's an elevator down, then move inside the big building in the center of Valley of Strength.
It appears you have to talk to Tal in Thunder Bluff before you can hand in the quest, so talk to Tal, fly to Orgrimmar (Send me to Orgrimmar) and then talk to Garrosh. The quest chain ends there, as far as I can tell.