C1 E2 in brief

Riding the adrenaline of the quarry battle, the party turns a rescue errand into paid work: Nostoc Greyspine contracts them to delve past the collapsed tunnels, find the source of the stitched creatures and whatever commands them, and kill it. The foreman Hieris reframes the job — weeks of stitched, mutating, agonized creatures and surface beasts drawn underground point to an intelligence deliberately making and herding them. After a failed second attempt on the warded arcane House Thunderbrand (whose archmage will deal only for artifacts brought up from the mines) and a shopping run at the one outsider-friendly shop in the city, the party rests and descends. Vex tracks a grisly trail — bodies dragged deeper instead of buried, two of them leaving no footprints at all — down an impossibly deep tunnel into a vast river cavern, where two umber hulks ambush them. Their mind-scrambling gaze forces the whole fight to be waged with eyes averted: it freezes Vex, nearly turns Grog’s axe on Tiberius, and the party survives only by improvisation — Scanlan snailing one hulk, Keyleth and Grog drowning the other, Vax killing the last over a pinned Scanlan. Deeper still they find a hidden duergar camp and the enemy’s shape: dark dwarves and a walking brain-creature whose psychic strike empties Grog’s mind to a catatonic husk. They win — Tiberius shattering the brain-thing, Percy wounding one duergar alive to question, Vex demanding surrender — but a dying duergar’s cry of “back to the master” names the hand behind it all. The episode ends on the cost: a captive duergar in hand, Kima still unfound, and Grog walked out of the dark with his mind gone and no way yet to bring it back.