This is the first class quest you will undertake as a warlock. It's purpose is to introduce you to your class trainer.
You must complete the quest  before you can access this one. Additionally, this quest is limited to orcs only.
Ah, while you were gone a parchment came for you, <name>.
I usually avoid dealing with warlocks if I can help it, but I think you should read it when you have time. If I'm not mistaken, it came from your newly-appointed trainer Nartok. He would have words with you when you're ready.
Finally, you've arrived... and discretely also. Good.
Our world is full fools, <name>. Even the mighty Thrall has greater flaws than most can see. He turns his back on the power needed to make this land our completely! We're not the same people who were manipulated and used by creatures from the Nether. We are our own people. We are proud... and we are strong.
And now you've joined our ranks also. Don't misunderstand, <name>. Just because you have access to power that many will be jealous of, it does not mean you will be accepted easily. Thrall allows our kind into Orgrimmar because we are still his fellow kin--he cannot turn his back on us, or we would become as pathetic as the humans who enslaved him. My point is: be careful. You can be powerful, but if you are foolish, then you are as good dead.
If you need training in spells then return to me.