Seven people received extremely mysterious letters. Jerry Pearson, the owner of a dilapidated castle located on one of the islands of Cornwall, invites them to a “special” reception, where each of the guests is assigned a specific role - the role of a character from the legends of King Arthur. At first, what is happening seems like a ridiculous joke, but soon Mr. Pearson declares that he has invited everyone present to witness his own murder. It is this statement that becomes the starting point - the “performance” begins. In the next few days, it is vital for these people to understand what is happening, unravel many mysteries and get off the island, surrounded only by harsh rocks and a raging sea.