I cannot find private Imarion / Scout Makha

From wow.incgamers.com

It's a Quest chain which has several steps. First steps is just on south wall of Hellfire Citadel - plans are lying on small table, pick them up. Don't forget to repeat it, as there are 2 quests available.

Second step is Sword/Shield which can be found just accross the road to south in small cap with hostile mobs.

Third step is cage with Imarion/Makha, continue south along the wall, you will reach spot with broken hut. Inside are cages - Imarion for alliance and Scout Makha for Horde. Talk to Imarion to get next step.

Fourth step involves killing Grenadire to get grenades. He walks around the wall from place where you are now and Hellfire Citadel. Kill him, then return back to Imarion/Makha and talk to him again.

Fifth step, use explosives on wall where big banner hold (guarded normally by two mobs) - this will bring out the mob you have to kill to get key. If it does not work, try be closer to wall. Or just wait, as the mob might have been recently killed by someone else.

Last step - just open the cage.