The Lucky Horseshoes (Nancy Drew Notebooks Series #26)

T-R-O-U-B-L-E. EVERYBODY KNOWS WHAT THAT SPELLS!
Nancy, Bess, and George are doubly excited. Not only are they taking horseback-riding lessons, but Bess is in the school spelling bee. And maybe her mom's lucky horseshoe earrings will help her win!
But now the earrings have disappeared. Good thing Nancy's around to help Bess solve the mystery -- because a good friend is the best good-luck charm of all!