Set in Rome, the heart of this novel is concentrated in a few chapters halfway through the book, an intense emotional collision between Lorenzo, a fourteen-year-old boy, and his half-sister, twenty-something Olivia, the family black sheep. Much of the author’s early effort goes into describing an only child completely self-contained in his family unit, with no apparent need for friends or outsiders. Exquisitely conscious of his mother’s worry on his behalf, Lorenzo eventually makes up a ski trip with popular friends for a week in an effort to assuage her fears—a week he has planned to spend in the cellar of their home.

Not a particularly likeable character, Lorenzo is a young teen obsessed with his physical flaws, the man hardly recognizable in the awkward boy’s body, frequently fancying himself able to morph into a dangerous, all-powerful being, hiding in plain sight from the mockery of peers; there is some relief in these comic-book fantasies. But Lorenzo has reason to question the wisdom of his plan to hide in the cellar as the days pass and he is bedeviled by cell phone calls from his mother, who demands to speak to an adult chaperone on the trip. The unexpected arrival of the impetuous, impossible Olivia into his secret lair changes Lorenzo’s idyllic hideaway from retreat to nightmare, Olivia in the throes of her own demons.

What begins with sarcastic enmity turns to rage, then a rapprochement of past and present as two lonely half-siblings recognize in one another what each seeks and form a bond neither could have anticipated—after much verbal sparring and accelerating physical altercations. Here the author is at his most effective, the push and pull of two individuals who barely know each other yet form a connection of great importance to each. Like opportunity taken or squandered, this is a moment in a lifetime, one that remains indelible as the boy becomes a man.

This small novel can be read in one sitting. While Lorenzo is not a sympathetic character, Ammaniti uses the boy’s awkwardness and lack of emotional maturity to advantage as his brilliant hideout is invaded by an equally out of control and older Olivia. Respite turns to ordeal as Olivia wrangles with her addictions, her behavior inciting a rage from Lorenzo that he has taken great pains to control of late. In their moment of confrontation, there is a psychological breakthrough for both characters, the sibling’s shared humanity made all the more poignant by the final resolution. Me and You takes but a short time to read but offers a memorable experience in a mutual recognition of loneliness and grief.