Go to the underground entrance

A crevice splits the hillside, half-hidden by roots and vegetation.

There are stone stairs and a sturdy iron door, but you manage to open it using a "knock" spell.
When you go downstairs, you notice a terrible smell, sour milk, sweat, and something more... rotten.

You walk through a bit corridors and you observe big horses in chains and also poor girls immobilized with pumps connected to their nipples. They are sedated and look at you with empty eyes.

When you reach the end of the corridor, there is a small opening to your left, like a garbage disposal tunnel. And a big man wearing a cow mask appears in front of you. He's huge and wears a cape with cow prints, and his big nipples are adorned with piercings. His hands, big as your skull, are glowing with magic.
He babbles some words in a deep voice.
"Prisoner, return to your duties! I need more milk!"

You can fight him, or use the small tunnel.