"Cute Poison" is the fourth episode of the first season of the television series Prison Break. It first aired on September 12, 2005 in the United States. The episode is directed by Matt Earl Beesley and written by series producer Matt Olmstead. The words "Cute Poison", one of Michael Scofield's (Wentworth Miller) tattoos, are a mnemonic for CuSO4 (copper sulfate) and H3PO4 (phosphoric acid), the two ingredients needed for the third part in his escape plan. Also, his new cellmate Charles "Haywire" Patoshik (Silas Weir Mitchell) notices Michael's tattoos and may expose his escape plans. Michael has to stop him and get his old cellmate, Fernando Sucre (Amaury Nolasco), back.