Grimfen

You arrive from Caerlin Woods through either of the two western entrances (4,13 and 7,25). Grimfen is large and ties several places together: a passage north into Obula's Hollow (17,3), one north-east into the cave called The Mireheart (37,7), one south into Ruins of Elderfen (24,32), and a second, southern Mireheart entrance down in the east (36,33). The resurrection shrine is in the middle (15,17) and a waystone for fast travel sits in the east (33,27).

Tentacles are burrowed all over the swamp and rise when you come close (for example 15,13). Every hit they land causes disease, so bring cures, not just healing potions. Wrathspinners and Stormspinners guard the egg sacs in the north (16,7), and Swamplings hold the ruins at the southern Mireheart entrance (37,29).

Evil Ents rise around the altar in the middle of the swamp (18,23) – and the same fight breaks out at the altar where you meet Grgla the Sleazy (23,24), a marsh creature who also trades. Win the fight and you can talk to him and buy and sell. The thing to ask about is the fog maze: he hands you Grgla's fish and joins you as a guide. The lost friend he keeps talking about is The Thing.

The Thing itself surfaces once from a pool in the northern swamp (25,13), lashes out with its Tentacles and sinks away again. You won't finish it here; the real fight is in The Mireheart. A lost dwarf wanders nearby (20,16) mumbling riddles: red roots in the dark drink whispers, some cages look like monsters, and you shouldn't kill every guardian you meet. Treat that as a warning rather than instructions; the roots come up in the level below the Mireheart.

There's a lever in the south that opens a gate (18,29). Down in the south-east a skull button slides back the secret wall beside it (32,28), and the grate door at the southern Mireheart entrance opens from a hidden button (34,32). Further east stands a metal door (42,31); what it opens onto, we can't confirm.

In the east a sign stops you on the road: "TURN BACK. YOU WILL GET LOST!" (31,24). It isn't bluffing. The fog maze beyond it is hidden from the in-game map (32,24), so you can't even reconstruct afterwards where you've been. Don't guess a route through it.

Grgla is the answer. Ask him about the maze, accept his help and let him lead you through. Touch the waystone in the east of the swamp (33,27) as well, so you never have to walk this stretch again.

Two chests sit in the west near the shrine. The first (11,18) holds a Hat, Ectoplasm, Potion of Minor Stamina, Mindwell Elixir, Rusty Sword and the Recipe: Ironhide Potion; the second (9,21) has the Recipe: Potion of Poison, Moonpetal, Potion of Mega Healing, an Embersteel Amulet and a Crimson Edge Ring.

A dead adventurer (16,25) leaves a Bloodstained Letter, Hardened Armor, a Hand Axe, a Bug Mandible and an Old Key. We don't know which lock the Old Key fits, so keep it and note where you found it. In the south-east there's a chest with the Shield of Wind (33,33), and further east the Alligator Gauntlets lie on the floor (45,19).