It's unbelievable, but it's true: a first-class international museum −the Reina Sofía− commissioned a work from a sculpture star, the North American Richard Serra, for its inauguration in 1986, The sculptor delivers a piece created ad hoc for the room in which it was going to be exhibited, The sculpture in question −Equal-Parallel/Guernica-Bengasi− consists of four large independent steel blocks, The piece is immediately elevated to a masterpiece of minimalism, Once the exhibition was over, the museum decided to store it, and in 1990, due to lack of space, entrusted it to an art storage company, which moved it to its warehouse in Arganda del Rey, When, fifteen years later, the Reina Sofía wants to recover it, it turns out that the sculpture – weighing thirty-eight tons! – has vanished, No one knows how it disappeared, or at what time, or at the hands of whom, By then the company that guarded it no longer even exists, Zero leads on his whereabouts, The mysterious disappearance is also elevated to the category of masterpiece, As the scandal acquires worldwide resonance, Serra agrees to replicate the piece and give it the status of an original, and the Reina Sofía, add it to its permanent exhibition, Between the non-fiction novel and the fictionalized chronicle, between the disparate and the hallucinogenic, Masterpiece reconstructs a case at the pace of a fast-paced thriller that leads to some disturbing questions: how is it possible that something like this happened? How does a copy become an original? What is art in contemporary art? What was the true fate of the famous, huge and heavy steel sculpture turned into air? Is it possible that it will appear one day?