You can find the gory details on YouTube videos, but basically get Karlach, but don't go kill the paladins yet. Run down along the river, she gets a ! over her head, but do not talk to her.
She wants to say, hey, we're getting a little far from them, what about your promise? But don't click on her.
Go over to the mountain pass entrance, since you are level 3, effortlessly do away with the Githyanki patrol, then walk up to the mountain pass. You should get the big cut scene. Then enter, you are forced into camp for a rest. Now it's Ok to click Karlach at her tent. Immediately click Karlach, she should finally say hey, what about the Paladins? Click yes let's go get 'em! She'll be happy, but the Grove will not be sealed and the quests not forced finished.
Normally one would use this to cheese the Helldusk armor, which normally kills all the tieflings because of the mountain pass entry.
Anyway, rest, view all the other cut scenes, cheese the armor if you've set up for it, then exit camp. You may be blocked from fast transport, but I think clicking the bedroll will work. Anyway, you should reappear on the Grove side of the mountain pass, never having actually entered apparently. Go save the Tieflings, deal with Auntie Ethyl, kill the Paladins. Only the Waukeen's Rest will auto-finish, but that's a different mechanism, sleeping after stumbling across the fire, so get your SpellSparkler first.
This lets you get the armor very early (you can cheese the Silver Sword at the same time) but nothing's stopping you from saving the tieflings first in the usual course of business, this trick is only useful if you want the armor very early and want to preserve Dammon, or maybe are a goody two shoes.
