The speaker of "somewhere i have never travelled,gladly beyond" is a total slave to his lover. He goes on and on about how she has total control over his emotions and there's nothing he can do about it. Rather than this being a bad thing, though, the speaker is really... really into it, and he seems to love her more the more power she has. Don't go thinking that the lover is some kind of bully, though. She manages all this with subtlety and a mysterious grace.
What gives the speaker's lover so much power over him is that she doesn't even know that she has it; he's possessed by her subtle, complicated soul. It's as sweet as domination gets.
The speaker's lover is obviously evil and manipulative, and she controls him by withholding emotionally. This dude needs to hit the road.