Stone is nearly shot during a meeting with a dealer. When an informant helps Stone, Mac is concerned about how it will effect Stone's already rattled state of mind. Meanwhile, Angie has established her first informant relationship and is using this to bust a drug dealer. Angie and Stone's contacts lead them to the same place, jeopardising each other's stings. Stone stays undercover and saves the guns deal and succeeds in bringing down the gun dealer. Angie's work reveals that Stone's informant had been using the gun racket to cover her own dealings in drugs.