10 Horror Movie Twists That Were Hiding In Plain Sight
7. Serial Killer Knowledge - Predators
In Predators, a group of strangers find themselves hunted by alien warriors on another world. The team consists of a cartel enforcer, a sniper, a RUF soldier, a mercenary, a Yakuza, a death-row inmate, a marine, and a doctor called Edwin.
Because each person has a history of killing, the team believe they were specifically chosen by the Predators since they would serve as challenging "sport" to chase. However, because one of them, Edwin seems harmless, they assume he was only picked to keep his teammates alive with his medical skills. But during the climax, Edwin is revealed to be a serial killer who is intent in killing them all.
Some viewers suspected there was more to Edwin than he was letting on since it didn't make sense why the Predators would choose him for their game if he wasn't as dangerous as the others. However, Edwin's sinister side is implied early on. At one point, he comes across a chemical and instantly recognises its toxicity. Upon the first viewing, you'd assume Edwin recognises the toxin due to his medical experience. But upon rewatching Predators, it's obvious Edwin has used this neurotoxin to subdue his victims many, many times in the past.