Try figuring it out

At the frontier of the skin no dogs patrol.
At the frontier of the skin,
Where I end and you begin,
Where I cross from sin to sin,
Abandon hope and enter in,
And lose my soul.
At the frontier of the skin no guards patrol.

At the frontier of the skin mad dogs patrol.
At the frontier of the skin,
Where they kill to keep you in,
Where you must not slip your skin,
or change your role,
You can't pass out I can't pass in,
You must end ans you begin,
Or lose your soul.
At the frontier of the skin armed guards patrol.