Stan found out that Rodger had sent for his wife and that she was supposed to be coming in to see him. Rodger had made some arrangements with almost all of the guards for her to service them in some way to pay for the favors that he wanted since he didn't have any money. Stan thought that he just needed one of the guards that he could count on to bring her to him first.
Before Stan had been planning on using her when he thought that would destroy Rodger. But now Stan realizes that it would have no effect on Rodger at all. So, his plan had to change. He still wants to talk to her first so that he can offer to pay Beth to refuse to do what Rodger wants. All he needs her to do is to go to Rodger and then refuse to do anything in front of him and all the guards. Then he would make sure that she got out without any of them touching her. It would leave Rodger in the worst circumstances of his life, with everyone looking for payment for the favors that he had been collecting.