10 Best Lost Plot Twists

5. Desmond Crashed Oceanic 815

It takes a truly great twist to answer not one but two of a show’s biggest unanswered questions. For the entirety of its second season, Lost teased viewers with the question of the Swan button’s purpose, which took on greater weight after Ben claimed that he had failed to push the button in time to no effect. The expedition to the Pearl station seemed to prove that the button was merely part of a psychological experiment, prompting Locke and Desmond to try and ensure that the countdown ran down to zero.

However, Desmond’s examination of the log printout from the Pearl led him to a chilling discovery, as he realised that the occasion when he had previously failed to press the button within the time limit coincided with the crash of Oceanic 815.

The precise cause of the plane crash had been shrouded in mystery since the very beginning, and the discovery that the Swan station’s electromagnetism was responsible represented a massive landmark in Lost’s mythos. It also raised the stakes of Season Two’s finale to apocalyptic levels, by proving that pushing the button was anything but a futile exercise, and that Locke’s attempt to let the clock run down could have lethal consequences for the entire planet.