10 Best Time-Loop Sci-Fi TV Episodes
1. Doctor Who - “Heaven Sent”
The Doctor is transported into a glass chamber inside a castle in the sea, where he finds that he is pursued by a cloaked figure. This brings about his childhood fears, so he makes his way around the castle in an attempt to escape his pursuer.
He finds hundreds of skulls in the water surrounding the castle and surmises that he is trapped in a torture chamber. He explores the castle, trying to learn its secrets so he can escape, and along the way, he locates odd clues/remnants of his predecessors. He eventually finds Room 12, where he is faced with a wall of Azbantium, a mineral harder than diamond.
He believes the TARDIS lay beyond the barrier, so he begins pounding on the wall but is interrupted by the figure, who mortally injures him. He crawls back inside the glass teleportation chamber, destroying his body. The Doctor is transported into a glass chamber inside a castle in the sea.
The Doctor realizes each time that he's stuck in a temporal loop, but he also learns that it was designed solely for him. He ascertains that he was trapped in his Confession Dial for 4.5 billion years before finally breaking through the Azbantium wall to find himself outside the Capitol on Gallifrey. He "came the long way 'round."