Istmo tells the story of Orlando, a translator who works from home for a film festival. He translates old Latin American movies from Spanish. In his parallel life he is an "influencer" in a customary and boring daily life, characterized by many small quirks, headaches and nightmares. His house is a maze, a cage he never leaves. His daily life: a system which is self-sufficient and independent from the world outside. Orlando lives with Amad, his roommate, an enigmatic figure with whom Orlando is constantly in conflict and who will provide an unexpected identity twist at the end.He is surrounded by colourful and mysterious characters, brushstrokes of his past, contrasting figures and evocations of a future that needs discovering (Agnese, his maid, once his nanny; Gina, a massage therapist and old friend of his with whom he had a love affair; Mrs. Topy, a happy elderly tenant living alone on the lower floor; the sensual neighbour, fond of getting totally tanned on the terrace and punctually peeked by Orlando; the picturesque South American neighbours and Antonia, his Spanish employer, master of life, with whom Orlando has a bond, apparently only a working one, based on turbulent video calls). Only Marina, a rider who regularly delivers him food, will succeed in opening up new horizons towards the "outside", just when his life will be at a crossroads. The entire film is a hymn to life and to the possibility of experiencing it to the full, "living it at first hand". The isthmus (Istmo in Italian), represents a geographical symbol which separates and unites, a subtle border with infinity and existence.