Mystery of the Midnight Rider

Some equestrians are up to more than horseplay in this third book of the Nancy Drew Diaries, a fresh approach to a classic series.
At the prestigious--and competitive--River Heights Horse Show, the prizes, which range from money to possible placement on the Olympic Team, are so highly coveted that anyone from the riders to the owners will do anything to win...even drug the horses Who's up to no good? Nancy, Bess and George are on the case