"The Last Defender of Camelot" is the second segment of the twenty-fourth episode of the first season (1985–86) of the American television series The Twilight Zone. It was based on the short story of the same name written by Roger Zelazny, and was adapted by George R. R. Martin.

London 1986. An elderly gentleman packs his car to go on a trip and he is accosted by three young thugs. He turns the tables on them and forces one of the thugs whose name is Tom to reveal that a woman paid them to perpetuate the attack. The old man forces Tom to take him to the woman and they enter a fortune teller's shop, where a woman is sitting in the dark. She reveals that she is Morgan le Fay of legend and that she knows the elderly man is Lancelot. Merlin, she says, is hiding in a cave in Cornwall and Lancelot is planning to meet with him. She warns that Merlin is dangerous and is not to be trusted. She casts a spell that sends Lancelot and Tom to the cave entrance, where Lancelot enters alone.

Merlin questions Lancelot about the state of the world and then insists that they work together to make Merlin king. Lancelot explains that the world has changed and that kings are mere figureheads and the people elect their own leaders now. He also tries to explain the modern dangers of war but Merlin is unconvinced. Instead, he demonstrates his power by animating an empty suit of armor to make a champion. They depart and join Tom outside. Lancelot finds they are now at Stonehenge and Merlin insists upon sacrificing Tom to completely restore his magic but Lancelot intercedes and Morgan le Fay arrives.

Magically summoning his armor, Lancelot does battle with the hollow knight. Meanwhile, Morgan le Fay stops Merlin from interfering with the duel but she is mortally wounded, and Lancelot prevails against the hollow knight. Merlin then points his staff at Lancelot and attempts to destroy him but Lancelot's shield staves off the attack and Merlin's staff is destroyed. Merlin then requests that Lancelot kill him but Lancelot refuses. Merlin ages rapidly and vanishes.

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