9. Ozymandias' Is The Architect Of Watchmen's Conspiracy (Also Rorschach's Identity)
While Ozymandias' reveal as the architect behind the apocalypse that takes place at the end of Watchmen is magnificent, it's also one that is telegraphed from the very beginning of the series.
Veidt's name alone is a pretty solid clue - as it originates from a poem written by Percy Shelley - and anyone who discovered this may have found some particularly telling lines such as 'look on my Works, ye Mighty, and despair!', which raises some less than subtle suggestions as to who may have been the mastermind behind the genocidal plot all along.
Although this is one twist that keeps its cards slightly closer to its chest, it's almost impossible for Alan Moore to not be tempted by a cheeky spot of foreshadowing - much in the same way we see Rorschach's true identity foreshadowed within his first-ever monologue within the comic: