House of Cards (novel)
Then Roger O’Neal’s girlfriend breaks up with him so he has a nervous breakdown. He is angry with Uruqhart so Uruqhart gets O’Neal drunk until he falls asleep and puts rat poison in O’Neal’s cocaine to kill him and make the murder look like a suicide. Uruqhart feels guilty about that so when Mattie asks him if he killed Roger O’Neal he kills himself by jumping off a balcony.