What is the story about Prindin and Kahlan and what he does?

The Mud Warriors show up and Prindin kills Tossidin. Prindin then shots a poison arrow into the neck of Chandalen. Kahlan is so weak now she can't fight back. Prindin tells her that he has given her just enough poison to slow her down but that she will live to be beheaded but that Chandalen is going to die in just a few moments. Prindin says he has been working for the Keeper for some time. Prindin takes Kahlan back to the Imperial Order camp where he tries to rape her. Kahlan is too weak to move but somehow is able to get a knife that Chandalen gave her in between them and Prindin kills himself falling onto her and the knife.