Eleven-year-old Maks Wilczynski has one dream - he wants to become a professional tennis player. However, instead of drop shots, he practices playing the cello, according to his mother's wishes. Only two people know his secret and help him realize his dream - his grandfather, with whom he secretly practices forehand and backhand, and his friend Ola, who wants to be a policewoman, but her parents dream of her becoming a tennis player.—G