Melanie gaslights Sloane into thinking she was also kidnapped.
SPOILERS: Considering the entire island is Melanie’s revenge fantasy for Nick, she gaslights all of the other characters into thinking she’s an innocent participant and that their fantasies are in their control. When it’s all her own machinations to cause their deaths.
The movie uses black eyes and eyes turning black to indicate that certain characters are inhuman. At one point, these inhuman looking black eyes explode and bleed
The movie starts with the scene of a girl running away from her kidnappers but she literally has nowhere to go as they already took her to the island and gets caugh, struggles and scream a bit but is taken again by them. If this type of stuff upsets you, you can always skip that scene, just know that it was a blonde girl.
One of the characters fantasizes abt being in the military. For a second it looked like the film wasn’t going to glorify it, but nope, it does exactly that.