Instructions
Travel into the cave by running into its entrance near the river.
Follow the natural path of the cave. There is only one way through the Hobbe cave; all side paths quickly reach a dead end.
Stick with Herman for as long as you can. At a certain point, he will run off in the direction of his son's voice, leaving you to deal with a group of Hobbes.
Catch up with Herman. He will have located his son, who is trapped behind a large door.
Run around the path to the right and you will cross through a large room. Once through, you will be on the path that leads to the other side of the locked door.
Run to Herman, who has found a way to get through the door. Herman's son has already become a Hobbe at this point, and he and a group of other Hobbes will kill Herman before you can get to him.
Fight your way through the rest of the cave. Eventually you will find a ladder that you can use to escape.