Ethereal Giant Spiders

What — Two giant spiders, permanently phased into the ethereal, lairing among the debris at the collapsed dead ends of the flooded water tunnels in the deep Menagoles Mines. Found in Session 53 as the party finished mapping the waterways; left unfought.

Threat — Unassessed. Never rolled for, never damaged, never damaged anyone. The GM counts them as one of the three remaining pips in the mountain alongside the bone dragon and the mining camp boss.

Observed traits (Session 53)

• Phased out by default. Visible only as an outline or silhouette — ethereal and spectral, not properly there. They phase in to attack and phase back out afterwards.
• Invisible to magic-sight. Fenric swept the chamber with his detection (30–60 ft) and read nothing — not the spiders, not anything they might be sitting on. While phased, they and whatever they hold are simply undetectable.
• Webs are the trigger. Physical web strands run through the debris; Silithane's bat familiar blundered into them and a spider phased in within the same breath.
• Bodies in the rubble. Corpses lie in the debris around them, possibly with loot — in the wreckage, in their stomachs, or under them. Nothing confirmed.

Tactics & behavior — Ambush predators with a fixed perch. One phased in and lunged at the bat; Silithane dismissed the familiar out of existence inside its closing jaws, and it chewed twice on nothing, worked out it had caught nothing, then shuffled back to its ambush spot and phased out again. No pursuit, no ranged answer, no attempt to follow the party across the room. Lash moved in close enough to be noticed and was not attacked.

Disposition to the party — Hostile to anything that touches the webs, but territorial rather than aggressive: they hold the dead-end chamber and do not leave it.

Open questions — Whether Fenric's anti-magic works on an ethereal creature at all is untested and new to him. Whether the webbing is what blocks magic-sight, or the phasing, is unresolved.

Status — Alive and unfought. Left in place at Session 53; still there and still skipped at Session 54, when the party walked out of the mine past them.

SUMMARY: Two giant spiders phased into the ethereal, ambushing from the collapsed water-tunnel dead ends of the Menagoles Mines — silhouettes only, invisible to magic-sight, triggered by their webs, sitting on bodies — encountered and deliberately avoided in Session 53 and still unfought.