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 has a certain 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, these people are vital to understand what is happening, solve many secrets and get out of the island, surrounded only by harsh rocks and the raging sea.