Something is amiss at the horse farm! During the night, someone broke in completely undetected and escaped with two very expensive saddles. The thief left no trace of a forced entry, and no tracks that anyone can find. Since Tine's cousin Gerrit is spending the day with Tine, Ina, and Alex, he offers to help investigate the pilfered items. Can the children locate the items before the thief sells them, or will they find themselves trapped in dangerous situation?