8 Science Fiction Movies Ruined By Their Twists

Possibly the most infamous sci-fi plot twist on this list, Signs is renowned for almost being a great film, p*ssing away its premise in the closing moments with an ill-advised plot twist that feels somewhat inspired by War of the Worlds.

When Earth is invaded by alien forces, a man and his family do what they can to survive, remaining in their remote farmhouse whilst it becomes ever clearer that the extra terrestrials aren't friendly. It turns out that they shouldn't have worried however, as a final showdown with a rogue green man reveals that water is their greatest weakness - you know, that thing that covers over 70% of our planet and falls from the sky sometimes.

It's an illogical choice at best, as why aliens would come to a planet with no protection or plan of action for encounters with H2O seems like a ridiculous choice for beings that are supposed to surpass our intelligence in every way. Whilst the film makes a lot more sense if it's viewed as a take on facing one's own demons, there's still a large gap between what was functioning as a fantastic thriller, and the badly CGI'd showdown it ended on.