Mabrouk is a poor, young fisherman. One day, he catches a magic shell which tempts him to ask for the hand of Princess Heart of the Day in marriage. From then on troubles start for this quiet, contented fisherman. Many times, Mabrouk tries to ignore the temptation of the shell, or even to get rid of it, but every time he tries it comes back with a different shape and with new tricks. Finally, he goes to the king's palace to ask for the hand of the princess. How does Mabrouk enter the palace? How do the three princes, who have also come to ask for the hand of Princess Heart of the Day, receive him? What is the last trick that the wonder shell performs? Both grown ups and children will enjoy this funny, exciting story.