Sister Dee runs a boot camp for bitches. Marina is her newest recruit, one in desperate need of some obedience training. Dee puts her through the paces, teaching her to stretch, suck and fuck on command, but that is just the easy part.
The man in the iron mask comes to mind. Shackled, hobbled and blind, she only needs to obey the commands she hears to save herself from the suffering. Keeping her concentration is not that easy when there is current running through her cunt, though. The best she can manage, in the end, is screaming at the top of her lungs for mercy.
And PD has his own, advanced, program for her. He will teach her pussy control in a whole new way. The training exercise is difficult and the punishment for failure is intense. If she has any hope of passing she has to learn from her mistakes quickly.