After his journey in Italy, Paul Heyse (1830-1914) wrote Ein Jahr in Italien (1853) and several short stories. Among them he composed Die Einsamen (1857). The story tells of a German painter who, during his stay in Italy, encounters Teresa and Tommaso (sister and brother) and becomes spectator and narrator of their lives. His words first, and those of the protagonists then, will reveal the sad events which led them to leave Naples and the Mediterranean Sea the loved and lived so close to. The Mediterranean becomes gradually and inexorably the true protagonist of the story. It dominates the scene, is always present, with its strength and flows. Its waters know everything, they hide secrets but, most of all, hide the truth. The sea is a mirror the protagonists fear to look in because they would see all their sorrows and faults in it. Thus, they reveal their whole complexity only when they get in contact with it, look at its waves from far or try to escape from it. The sea is always there, and, even if tempestuous, it is never cruel: its storms are due to the secrets it shields. This work proposes to interpret the characters of Die Einsamen by means of their relation with the sea. The Mediterranean Sea of Paul Heyse is the key to discover their deepest nature: it is the guardian of their hidden and unsaid desires and pains and the only one that could help them to face life and truth.