A serial killer, nicknamed Le Ver(s) Solitaire (The Lone Worm) for the alexandrines left at the crime scenes, is spreading terror. Under the orders of a commissioner, Clarisse Sterling, a rookie in the crime squad, can only rely on her instinct, 200g of chouquettes and the virtues of a well-placed pineapple to solve this investigation and save her skin.

Rémy and Mélanie live next door to each other in Paris but have never met. The two thirty-year-old Parisians search for connections online, but never have much success. Falling deeper into loneliness and depression, both decide to start attending regular therapy. With the help of their therapists, they uncover the real roots of their issues, and find that the connection they were both searching for is much closer than they thought.