This is a very long quest that involves traveling across the many different areas of Norrath. You will have to find 26 runes to learn the draconic language to proceed to the next quest.  To start this quest you must be at or above level 45.  You must have the giant language (Krombal) in order to speak to Lord Nagafen's Assistant Mojo Dominus.  If you do not have this then you can't proceed to the next part after reaching Nagafen's Lair.

To start this quest you must first hail a sage just outside of the exit of the Temple of Sol Ro Location -180 0 -500. He will tell you that his master is in trouble and his master needs to be rescued. This is mearly a flag to let you get into the appropriate Maiden's Gulch instanced zone "Rescueing The Sage". Follow the path behind the sage to find the entrance to Maiden's Gulch. It is there where you will enter Maiden's Gulch: Rescueing The Sage instanced zone where you will have to fight a nasty boss.

This fight isn't hard due to the recent expansion packs adding in achievements and higher levels.  However if you are below level 50 it can be a bit of a challenge if you are not prepared for it.  You will face a level 52 epicx2 drakota with three minions. The order of the fight is taking down the Drakota Inquisitor minion, then his two other minions and finally the boss himself.   

Once you have defeated the boss you will go up and talk to The Sage of Ages to recieve the quest To Speak As A Dragon. This is a Hallmark quest and if you have Kingdom of Sky it will give a good chunk of AA points upon completion. With the quest in hand your first task is to head to Solusek's Eye and proceed down to Lord Nagafen.

Unfortuantely it is pointless to try to "invisi" down to the door to Lord Nagafen because most of the mobs if not all of them see through invisibility.  However you can bypass alot of this if you use a Gnomish Parachute to jump down the huge main shaft at the top.  If you time it right using 3 charges you can cut your travel time in 1/2.  You can also have a conjuror "CoH" you down there.

Upon entering Nagafen's Lair you will learn quickly that the mighty dragon refuses to talk to you in your Norrathian Tongue.  Speaking to Mojo Dominus you will find out you need to speak the Draconic Language.  Your next task is to head to the Oracle Tower in Antonica to speak to the Sage of Ages.

Once you speak to the sage of ages you will be given a task of finding 26 draconic runes that are scattered across Norrath.  You will need access to the lower depths of the Obelisk of Lost Souls (Door of the Creator) to two of the runes. You can find all of the draconic rune locations here.

With all the runes in hand head back to the Sage of Ages who will teach you the Draconic Language. If you plan to do the Kingdom of Sky Claymore quest line you will need this language quest.