In "Sandor - Bat with a Brain," the boy Jendrik and his talking bat Sandor have found a treasure. With the reward money, Sandor and Jendrik go on vacation together. Naturally, they head to Sandor's homeland: Transylvania. The journey itself is thrilling. Upon arriving in Transylvania, the real adventure begins! Sandor and Jendrik pursue a thief. They roam through fortified churches, secret passages, and dark forests. But then their chase takes an unexpected turn.