10 TV Shows Which Completely Changed Their Premise

4. Dollhouse

Like Angel, another show from Joss Whedon's stable, Dollhouse initially relied on self-contained episodes, which explored the missions undertaken by mind-wiped human operatives called 'dolls' who were implanted with new false memories each week. It was Alias starring Eliza Dushku, in other words, with sci-fi elements thrown in. The first handful of episodes were consequently quite dull until the overarching plot began to take effect, and the show began to explore the roots of the doll technology and its potential misuse.

By season two, Dollhouse had a firmly established mythology and the dolls were beginning to recover their individuality to face the sinister corporation Rossum. The weekly assignments disappeared after the first few episodes and the series built to its game-changing series finale, then dropped another bombshell when it revealed a post-apocalyptic future set barely ten years afterwards. It had utterly outgrown its original premise, but ratings had already diminished beyond repair.