Every summer, Henri goes to visit his grandfather Jacques. It's paradise there! Jacques lives in a charming house by the sea, loves to cook, and knows all the names of seashells. One day, when the sea is too rough for swimming, he explains the phenomenon of the tides to Henri. Henri discovers that these movements of water resemble the waves of emotion that sometimes pass through him. Through breathing exercises, Grandpa Jacques teaches him to tame his inner tides, so that his loved ones can discover his most beautiful treasures.