When you watch Doctor Who Season 9 Episode 11 online, the Doctor finds himself trapped in a castle that changes configuration like a puzzle box. With nowhere to run and no way out, he is also pursued relentlessly by an untiring creature called the Veil, which will kill him if it catches him. All alone, he must follow a chain of ominous clues to discover the way out of this nightmarish prison. He turns to a mental figment of the lately-deceased Clara Oswald for companionship, to provide him advice and and audience to explain things to when there is no one around but him. Each clue leads to another obstacle, seemingly more impassable than the previous, but the true horrifying nature of his predicament has yet to be revealed. Will the Doctor ever escape from his puzzle box prison, or will he be trapped there forever? Or will he make a deadly mistake and get caught by the Veil, thus ending his long life permanently? And what is that under the water surrounding the castle? Find out what happens to the Doctor when you watch the epic penultimate episode of the season, Doctor Who Season 9 Episode 11, online!