i've completed the Mage questline, been around all the court wizards, general goods vendors and tried both Tolfdir and Dravynea and still no dice.

Yeah, i could use the dragon shout, however, i'm level 35 and don't plan on doing the MQ,.

Any help greatly appreciated.

Quest:

http://www.uesp.net/wiki/Skyrim:Infiltration

Haha

Cheers! I've done that quest twice with previous characters and forgot all about that one.

You don't even need to do much either (like clear the whole dungeon which is for another quest).
Just climb up the walls, open the gate and you're done.