A Girl Scout troop in Los Angeles came across one bad cookie when a shopper gave them a counterfeit bill in exchange for some Thin Mints.
Launa Archer was handed a $100 bill in exchange for five boxes of cookies and $75 in change, which made her mom suspicious.
"My gut said 'Don't take it,'" mom Laura Archer told KCBS. "The other side of me said, 'But we're the Girl Scouts, who would do that?'"
Launa and her mom contacted the police, but as they stayed at their booth outside a grocery store in Orange County, a woman approached them and asked if they were still selling cookies.
"She asked what was going on, and I told her what happened." Laura Archer said. "She went all the way home and came back with $100."
Launa said the Good Samaritan did not even accept any cookies in exchange for the donation.
"She said, 'I didn't want your daughter to have a bad experience, please take this money,'" Laura Archer told KCBS.