For members of the Detective Club, vacations invariably turn into an exciting and sometimes dangerous investigation. So this time Holly, Tracy and Belinda have to uncover another secret. On the eve of the opening of an equestrian competition, two valuable racehorses were stolen. Moreover, one of them - a stallion named Meltdown - belongs to Belinda. Young detectives manage to find out that the criminal keeps horses on an old abandoned farm. But how to get there? After all, until now only one road was known - through impassable peat bogs...