10 Clever Ways Horror Movies Foreshadow the Ending

In Leigh Whannell's loose H.G. Wells adaptation, Cecilia finds herself harassed by her supposedly dead partner, Adrian Griffin. Unfortunately, nobody believes Cecilia, since Adrian attacks her while wearing an invisible suit.

Near the end of this 2020 picture, Cecilia shoots her tormentor dead, just as he's about to kill her friend Sydney. To Cecilia's surprise, the invisible man turns out to be Adrian's brother, Tom. When the police discover Adrian imprisoned in his house, it looks like Tom was the mastermind behind all of this, but after Cecilia deduces Adrian and Tom had been in cahoots from the beginning, she kills her abusive partner, ending his reign of terror.

Though the duel-killer reveal was meant to blindside everyone, there's one clue that Adrian wasn't acting alone. When Sydney is attacked, she pepper-sprays the unseen perpetrator, causing him to fall to the floor. As she tries to escape through the hallway, she's knocked over by one of the Griffin brothers in a scene that happens so quickly that most people don't realise Adrian wouldn't have time to rush in front of Sydney and stop her since he was immobilised in her room a second earlier. 

It's a small detail but it gives the game away before Cecilia works everything out.