Lumi tosses a dagger up, and it lands pointing south. "That way. Any way but the way we came would do, Scarloc thinks we're headed back to the broken tower so the the doppelgangers will think so too."

"And what if your sprite leads them to our true destination in ignorance? You'd better summon them back once we're hiding."

"Doesn't matter, if they catch us here first!" Fala says, also appearing. "C'mon, speed over stealth now, Mitrol'll clear the tracks."

She takes the lead towards the rubble-pile to the south, running up the sides of trees with an uncanny adhesion and swinging off branches with her whip for the height to guide their route ahead between more of the magical disturbances.

From behind the group comes another stilling of the air, that strange release of tension, then another. 

"They have a spellcaster, and it's figured out the trick."

In the magical quiet, a voice can be heard, distant but clear, singing a wordless elven melody from beneath the mound of wreckage. From further out echo demonic calls, cackles and hooting Abyssal cries.

The rubble rises a quarter mile into the sky and stretches nearly as wide along the ground, a mixture of elven and Netherese structures crushed together. Each time another of the disturbances in the Weave is eased by their pursuers, the remaining tangles flare and dance wildly, the singing becomes a little louder, and the colossal pile of rubble shifts a bit.

After a few such instances, it becomes apparent that the shifting is from the elven masonry moving back together, missing pieces replaced by the darker Netherese stonework. A tunnel becomes visible at the base of it.

"Inside!"

"Is it stable?"

"Do you have a better idea?"

Despite the destruction outside, the tunnel is in fact in good repair. What little debris or clutter is present is migrating outside with each pulse of silence. 

Once everyone has made it forty feet in, Mitrol drops his emanation of concealment and casts a new spell. The stone of the tunnel behind them extrudes spikes and thorny barbs, like the stalagmites and stalagtites of a natural cave or the tongue of a cat. The next moment, the colors and shadows shift to hide the hazardous terrain.

"That gives us ten minutes, unless one of them can teleport."

"They have been using a lot of spells... Or else they've found a way to use cantrips for the untangling."

Ahead, a bronze placard is mounted above the doorway. In Elven, it reads:

Entering the arcane sanctum of Quaryl Tellasarim, lorenorn of Myth Drannor. Enter this place and learn, oh seekers of truth. May Mystryl guide your way.

"A lorenorn! We must have the right place. A sworn protector and tutor of our people will see those doppelgangers off easily."

"...kessuk! Doppelgangers, we need to worry about impersonation and replacement." 

He thinks for a moment. "No, Mitrol is likely clear, a doppelganger druid would be very unlikely. You had eyes on Fala the whole time? That leaves myself and Lumi. Lumi can resummon her sprite, but I don't have any spells that another wizard couldn't copy."

"Moonbeam exists."

"As a last resort! I'm not some freak of nature like Fala, a few moments in that would kill me."

"Scarloc can use their Heart Sight. Speaking of."

The sprite appears with a faint pop, this time from being dismissed and resummoned instead of ending their own invisibility.

"His heart's of law alone, as was he last. The monsters are outside, we should move fast. My warning shot struck not their hearts afear, once through the warps they will be coming here."

They vanish again to flit ahead as the group's scout. The others follow to stick within the 60' range of Lumi's telepathic link to her familiar.

"Why aren't I Good? I do Good things all the time," Ivaebhin mutters under his breath. 

"Another one of the things up ahead, says Scarloc. Room's full of books and floating glittery shields."

"Abjuration. I have Mage Armor prepared, but it's touch, it might not work so close... No, I can cast it at a distance and then deliver it up close, nevermind."

He does so, following the sprite into the room and the pulled thread of the Weave is restored.

"One more of those, then two more of my second-level slots, and then I shall need a break to study my spellbook."

He takes one of the books from the shelves, opening it. "Property of the lorenorn."

"Shouldn't you be worrying about curses and checking everything first?" Fala asks. "I have a distinct memory of a lecture on that topic when we found that chest."

"This is a place of learning dedicated to Mystryl, she may be dead but to bar others from magical knowledge would be anathema to her. Besides, a lorenorn owner is all the protection these books could ever need."

He keeps reading. "This whole room is dedicated to the study of Abjuration, the pulled thread may have emerged here for that reason. Mythals are predominantly built around Abjurations, and this tome deals with the role of that spell school in the creation of intelligent items which ties in with the sentient mythal hypothesis..."