Waves is inspired by a short novel of Robert Louis Stevenson, The Ebb-tide, written and published in 1894, the year of his untimely death (Stevenson was 44 years old).

After months of living a solitary existence, Lenny, 34, picks up his kids from school. Every year he spends a couple of weeks with his sons Sage, 9, and Frey, 7. Lenny hosts his kids within a midtown studio apartment in New York. During these two weeks, he must figure out if he wants to act as their father or be their friend. Ultimately, their trip upstate results in complete lawlessness taking over their lives.

Rome, Esquilino, summer. Rossella returns to Rome after years of absence and returns to her home, rented to her friend Salvatore, the set designer. The woman is gripped by an evident depression and wanders around the city that she does not recognize and that no longer recognizes her. People have changed and Rossella finds no one capable of answering the obsessive question that has plagued her for some time: "How can I disappear?"

When an innovative modern architect flees post-war Europe, he is given the opportunity to rebuild his legacy. Set during the dawn of the modern United States (in Pennsylvania), his wife joins him, and their lives are forever changed by a demanding, wealthy patron.

Gheni and Gherti, two young Albanian immigrants who live in Rome and work in a restaurant, settle in the home of the photographer Corrado, who makes friends with the first. In a torrid and empty city for the summer holidays Gherti, more restless, binds with Lino, an old Sardinian who every day accompanies his mentally ill wife to the city. Gheni instead continues his little "climb" in the restaurant and strengthens his friendship with Corrado.

Police inspector Sciarra, struggling with an identity crisis, and Domenica, an orphan who would like to know about her mother, spend one day together along the streets of Naples. It's Sciarra's last day of work and he has to take Domenica to the morgue, to identify a man who might have raped her. To Domenica, Sciarra is a father she never had, to him she is the daughter he couldn't have.

On the edge of a road that leads out of town, some Nigerian prostitutes pass the time on sagging sofas, bargaining with white clients for their bodies and their thoughts. On another street, some Slavic boys wait to be hired as bricklayers, but they are willing to do any kind of work. At night, an Egyptian works as an illegal in a gas station.