Robson steps up his evilness and swears revenge on the Muslims who beat he and Schillinger in defense of Beecher. Robosn starts his evil deeds by taunting Said and all the Muslims every chance he gets. While waiting with Schillinger to return the pool table, Schibetta arrives and attempts to shank Schillinger. Robson comes to Schillinger's defense and soon he, Schillinger and another Aryan proceed to rape Schibetta. Robson soon turns his attention back to the Muslims and brutally tortures and kills Lalar Allah. Just when Robson's rampage escalated, he reluctantly goes to the prison dentist who informs him that Robson that gum implants are needed. Furious, Robson barks orders to the Indian dentist get gums from a white person for the procedure. This infuriates the dentist who after performing the procedure, reveals to Robson that a black person's gums were used. To make matters worse for Robson, the dentist pays Poet to spread the secret about Robson's gums. This gets Robson even more angry and he attempts to cut these gums from his mouth while he numbs them with heroin. This fails miserably and Schillinger is forced to consult with the grand leader of the Aryan nation on the matter. Since now Robson has "black blood" in him, he's not considered pure and Schillinger kicks Robson out of the "Brotherhood".
Season 4 Part 2
Robson begins to question Schillinger's commitment to the Aryans after he observes Schillinger meeting with the Rev. Cloutier. Robson and Hoyt visit Cloutier to convince him to leave Schillinger alone. Robson then stabs Beecher's brother in a revenge for Hank Schillinger's murder. Robson and Hoyt go to Leroy Tidd to enforce a deal he made with them kill Said. When this plan fails, Robson talks a new Aryan recruit into killing Said only his plan backfires and Tidd becomes the victim. Schillinger orders Robson to kill Beecher after he hears that Beecher's up for parole. Robson tries but is unsuccessful and get thrown in the hole. Robson and Schillinger see Beecher in the library and begin taunting him about losing his bid for parole. Just as things get nasty, Said and Arif come to Beecher's aid which results in Robson and Schillinger getting stabbed.
Season 4 Part 1
Robson continued to support Schillinger in his schemes of intimidation. When Querns transferred many of the white inmates out of Oz, Robson joined his Aryan brethren in Gen Pop also.
Robson continued to taunt Cyril O'Reily and gets into a fight with him in the cafeteria. When the boxing matches begin, Robson takes to the ring against Cyril only, Ryan spikes Robson's water bottle with drugs. Robson becomes disoriented and gets knocked out by Cyril.
Robson forces Beecher to perform oral sex on him. While this happens, Beecher bites off the tip of Robson's penis. Robson then gets more closely involved with Schillinger and his schemes with the Aryans.