Watch An Anatomy Lesson for Free: How to Stream the Movie Online at 123Movies. . In 1972, Carlos Mathus's provocative play 'La lección de anatomía' opened in Buenos Aires. He thus became a renowned author and director, and the play had an international uninterrupted run of thirty years. More than forty years later the author asks himself about the current relevance of the play and embarks on the adventure of a revival, an odyssey that will take a definite toll on his spirit, his health, and the work itself.