10 Movie Endings That Left You Speechless
3. Oldboy
Park Chan-wook's masterful mystery-thriller Oldboy serves up a boatload of WTF in its seriously unhinged third act, where it's revealed that protagonist Oh Dae-su (Choi Min-sik) has been unknowingly romancing - and, yes, sleeping with - his own daughter, Mi-do (Kang Hye-jung).
The two falling in love was set in motion by the villainous, vengeful Woo-jin (Yoo Ji-tae), due to Dae-su inadvertently causing his sister's suicide many years earlier.
With his revenge plan carried out, Woo-jin kills himself, and the film's final scene takes place some time later, with Dae-su visiting a hypnotist to have his knowledge of his incestual act wiped from his memory.
Mi-do then finds Dae-su and the two embrace, but Dae-su's initial smile quickly turns to a grimace, suggesting that the hypnotic memory wipe may not have worked, or at least that on some level Dae-su still knows the truth.
It's a complete mindf**k of an ending that makes a second viewing feel totally necessary. Once you've picked your jaw up off the floor, that is.