WARNING! SPOILERS: This post contains spoilers and speculation for the Doctor Who Series Nine episode Heaven Sent. Heaven Sent drops us into the middle of the twelfth Doctors personal hell. Hes trapped inside a video game where an endless series of repeated actions always lead him to the same spot. His choices are to reveal sensitive information, to embrace death or to reincarnate and endure this unique brand of torture again and again. Theres no way to beat the software so the Doctor comes up with the only way to win the game. He rips a hole in the hardware one punch at a time. There are two speaking parts in Heaven Sent, and of those Clara delivers two lines as a figment of the Doctors imagination. There is a monster but it presents more as monolith than living creature. This is Peter Capaldis show and his performance is a revelation. Its impossible to avert your eyes as the Doctor moves through his thought processes and emotions only to arrive at a horrifying conclusion. This episode has nerve. It never sways from its determination to push the Doctor to the limit. There is no sympathy here, only a presentation of the facts and what needs to be done to escape from the situation. Steven Moffat took a risk and it worked. Heaven Sent is brutal, brilliant and one of the best Doctor Who stories of all time.