Watch Echo Sonata for Free: How to Stream the Movie Online at 123Movies. . In the 1950s, a communist country. The film follows a retired detective who investigates two enigmatic murders. Both murders are connected to a murder exposing an old secret about a corrupt officer that causes controversy throughout the city and alerts the political security. As he uncovers clues, the detective plunges deeper and deeper into a maelstrom of political and personal intrigue that leads him to a final revelation.