There is a port in house "J" that will take you to an undead area, this is where you can start the "Delera" quest chain. After you complete this chain it will open up the Necromancers Lair quest.(Same location, but down the hill from the 3 tombs where you do the Delera quests) I got stuck paying 10,000 gold to do the quest, but after you do it once it is repeatable. You only need to pay the 10k gold if you want the item rewards, however just to repeat the quest costs you nothing. The first time we ran thru it took us 35 minutes, and we were all amazed at the 5k+ exp, so we did it again, in 26 minutes, and the third time in 22 minutes.(We were going to do it again to try to do it faster but I got wife agro so had to go) Be advised this is a level 8 quest and it says "Very Long", but we skipped most of the "optional" stuff and just completed the quest. For example, when you first go in you only NEED to pull one of the levers it looks like an "R" with an extra line thru it. Then just go thru the door it opens and continue, without hitting all the other switches.
Even after you repeat this a few times the penalty to exp is still worth it, and you can easily do it with a "decent" level 5 group, or an average level 6 group. Also at the very end of the quest there is a solo boss you see thru a gate, you need to have everyone kill him very quickly as he starts massive spawns when you attack. When he dies(within 5 seconds if you do it right) all the stuff he spawned will disapear, excpet a few othe mobs in the room. you MUST have a Rogue on this quest as there are three chest at the end, and 2 of these are locked. Also there are quite a few traps that cannot be disarmed, just "ninja jump" them.
I greatly encourage you to do this quest NOW, as this will most likely get nerfed soon like Red Willow.