Nedyr leads the way through the chamber slowly, carefully stopping before each step to determine where the next trap may lie. The going is slow, and Edvard is very visibly bored by the procedure, but the group successfully makes it to the far door. The howling wail is most certainly from somewhere beyond - but the door is locked.
In your search, you found another two of those strange switches as well.
As Edvard pressed against the door with all of his might, Delia quickly ran around the room pulling each of the levers. As quickly as she pulled them, however, the ancient spring mechanisms within each creaked to life, returning the levers to their resting positions within moments. By the time Delia got to the original switch again, the other two had already returned to the "off" position (or, at least, what was assumed to be the off position).
Meanwhile, the door shrugs off Edvard's feeble attempts to force it open.
As the three levers are pulled in synchronization, the grating of metal can be heard from within the door. With a loud click, the mechanism locks into place, and the door slides ajar slightly. The adventurers' light dimly filters through the crack, but it is impossible to tell what lies beyond. Fortunately, the three levers stay pulled - so you shouldn't have to deal with this lock again.
Edvard wasn't much for taking small steps in life. He felt that any sort of hesitation led towards indecision - a big indicator of low self esteem. Whatever was inside the dungeon would have to deal with him - and he was never alone.
"We are a pact...a pact of wolves. started Edvard as he looked about his teammates while they engaged the current situation.
"Look at us - we're no different than Kassen in his day - mind you, he didn't have a mighty but undead scared baby sister. ha! But, time to meet destiny head on! jeered the Tirel troublemaker as he stands within the doorway.
Looking upon the engulfing darkness, Edvard issues out a challenge.
"COME FORTH YOU RAPSCALLION. COME FACE THE MIGHT OF THE TIRELS!!!" belted Edvard, as the darkness accepted his plea.
Sevrin shields his light-pebble so as not to spoil Delia's night vision and waits nervously for a few heartbeats, listening for the sounds of Delia being devoured. If none are forthcoming, he'll still let Edvard go first.
Beyond the doorway is a narrow and dusty hallway - to the right, it leads off to a turn in about ten or fifteen feet down the corridor. On the left, Delia peeks around the corner and sees a doorway at the far end of the hall, maybe thirty feet away. Based on the volume of the wailing, one can only assume it's coming from behind that doorway.
Delia's initial efforts to open the door fail miserably. Oh, okay. It's a push door.
The door seems to be stuck - it's difficult to tell whether its simply locked or has been barricaded shut. You do, however, notice several old and cracked bones strewn across the corridor in your attempts to open it. Additionally, the moaning coming from the far side of the door suddenly stops in response. Only an eerie silence lays across the crypt.
"I was waiting for this moment..." intoned Edvard as he began to rev up energy.
Hefting his body weight behind a wooden shield aimed at the door, Edvard tightened up while making growling noises. His salivation dripped on the floor, filling the air with a dripping sound.
"One...two...AIIEEEEEEE!!!!!" he screamed while charging towards the door.
And in that moment, Edvard had put everything he had.