"Cute Poison" is the fourth episode of television series Prison Break. It was 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.