Find the source of plague in Heaven's Peak - part 3 Overlord Guide

Take your waypoint to Heaven's Peak and head to the city (left and across the bridge), but not before taking a few reds with you. Once in the city, turn left and walk to the stairs (#1) and up. Follow straight towards some burning barrels. Send reds to them and watch out for the black knights who'll show up there so kill them. Go sightseeing if you will - there's some gold and other stuff to loot around. Go down, turn right and head up the stairs - you'll see a fire barrier (#2) and some zombies so send your reds to do the job.

Listen to some peasants and... kill them when they turn into zombies! Send your reds to take care of the fire around and keep fighting the bastards that keep attacking you for some reason. There are spawning pits to the right from the path (#1) so get yourself more soldiers if you need. Head up the stairs now - see the place some guys with beer are coming out of (#2)? - it's called Halfway to Heaven Inn. Head on in!

Once inside, break the barrels to your left and follow that guy in red cloak (no, he's got nothing in common with Red Hat!). Take the door to your left (#1) and walk along the corridor. Break the barrels in your way and kill the rats (quite many of them). Then break the door on your left and the next way on. Now enter the room full of red-cloaked guys (#2).

Break another door - on your left - to get the spell of more minion control (#1). Now you can have up to 30 minions to dispose of! Head on to the door to your right and turn the wheel behind it - it opens the door that's closed behind the guy in red (loot the room before following him). Send minions to the mechanism through the gap in the wall (#2). As you might have guessed, a few monks will attack you immediately. Bring them down and go to the gate left upstairs.