This quest was marked obsolete by Blizzard and cannot be obtained or completed.
Speak with High Explorer Magellas in Ironforge.
Well <name>... we seem to be at a temporary dead end here. We know what we need - the Plates of Uldum - but we have no idea where they might be. We'll need to do quite a bit of research on this to come up with a solid plan of attack. I have a couple ideas where to start looking; I have high hopes that soon, we'll be asking you to head out and recover them.
The High Explorer needs to be informed on this, <name>; no doubt, he also wants to thank you personally for once again aiding the League.
We're all in agreement then - the best plan of attack is putting this on hold until we can narrow down the areas where these plates might lie hidden. You've brought us this far <name>, and I hope you will be the one to head back in to the field to unlock Uldum for us all!
Allow me to give you this honorarium in the meantime; this should cover any expenses you've encountered in assisting us, and a little something extra. Be sure to check back with us soon... Uldum beckons!