October 1787. Wolfgang Amadeus Mozart arrives in Prague for the premiere of Don Giovanni. But behind the applause and the crowded theatres, a shadowy conspiracy is brewing. A secret society of Freemasons, known as the "Keepers of the Silent Chord," believes Mozart’s music holds the key to an ancient alchemical formula – one capable of controlling the will of kings.
When a close friend of Mozart is found dead under mysterious circumstances, the composer is forced to investigate. Armed only with his genius and his notebook filled with musical sketches, he must navigate Prague’s dark alleys, grand ballrooms, and hidden lodges. Each melody he writes becomes a clue, each opera rehearsal a dangerous game of cat and mouse.
During the second act of Don Giovanni, a masked figure slips a cryptic score into Mozart’s coat. The notes, when played on a harpsichord, reveal a hidden map of the city’s underground tunnels. This event leads Mozart to the first true clue: the murderer is someone within the theatre company itself.
Following the map, Mozart discovers a forgotten laboratory beneath the Old Town Square. There, he finds a mirror that reflects not faces, but musical notes. By playing the correct sequence (a fragment from The Magic Flute), he unlocks a secret chamber containing the stolen formula – and the identity of the traitor.
While the conspiracy is fictional, the game is deeply rooted in real history: Mozart’s love for Prague, his Masonic affiliations, and the mysterious circumstances surrounding his late works. Every location – from the Estates Theatre to the Clementinum library – has been faithfully recreated based on 18th-century engravings.
“Prague understands me,” Mozart once wrote. In this universe, Prague also holds his greatest secret.