The Sub is easy prey!

Taking out the possible witness seems like the most logical choice, so you go for her first.

A quick dose of chloroform on a rag takes her out from behind, especially given that she was just worn out by her Mistress.

Some time passes and the woman awakens, but something isn't right...

She can't see.
She can't move her hands.
It is dark.
Is this metal?!?

You took her and moved her to a 'safe' location.
Well, safe for you, that is.

She struggles in her new condition, unaware of just how cruel and unusual this bondage is!
She tries to stand...

...so you help her out.

You push the button and the winch pulls on the rope connected to the giant ball of metal holding her head hostage.
It raises her up against her will and begins to limit her mobility even more.

"Are you comfortable," you ask, your voice coming through little speakers in the metal domes, "I sure hope so. You've been out for about, oh, an hour or so."
"Who are you? Where's my Boss?"
"Your Mistress, you mean? Yes, I saw your little fun before I took you. In fact, I know what you like thanks to that."

You begin to strike her with a cane across her chest and stomach!

She doesn't cry out in pain as you punish her.
She moans with delight.
You knew it!

"That was just the warm-up. Here's the real fun for you," you say, moving a vibrator in close.

She's all worked up, so this won't take long.

"You know what to say when you want to cum," you say.