CM2: Death's Ride
CM2: Death's Ride is Garry Spiegle's 1984 followup for the Companion rules. In it the mage Ulslime (LOL) has sicced the Army Of Darkness upon Two Lakes Vale, and generally trashed it. Your job is to un-trash it, by seeking out the Dread Stone of MacGuffin and destroying it.
The adventure takes place After, but there's a map for Before as well in case you wanted to come here during its heyday before it all went to braaains.
The designers set this one in Norwold on the assumption you're playing it alongside CM1: Test of the Warlords. It's clear that Spiegle himself never read it. He thinks Ericall works for Thyatis, and the baddie is an Alphatian. That's the limit of the module's connection to the Known World. So feel free to place it anywhere there's a mountainous frontier.