So curse the old guy's sudden but inevitable betrayal. Because Elindra's spider-talking was non-verbal, he didn't notice her doing that - instead he focused on Murmei's knowledge of different languages, and him speaking with the giant in particular, to decide he was a demon and ... battle ensued.
RIP crazy old man.
We found the Tomb of Horrors, or at least the Cairn of someone or other. The door was locked, but we made it unlocked and headed inside. It was full of pit traps. Fortunately (even the spider-weary in the party agreed on this term) Elindra has a pet spider who can crawl on things other than the floor.
Eventually we found a big room with a ritual anvil, so the party decided Murmei was somehow best suited to become a blacksmith and turned an ordinary axe into an axe that makes you blind when you carry it, even if you're dragging it behind you on a rope. He also only narrowly missed out on taking permanent corruption during the forging, and wasn't keen to have another go making another perfectly usable weapon useless - despite both Valgai and Elindra thinking it would be great to have a blacksmith in the party.
It was basically a good old-fashioned dungeon crawl, and there's more where that came from!