***Spoiler ***SPOILER ****SPOILER ***
I thought the ending was obvious.
Island on fire is bound to catch someone attention! Cutting the head off was for the unbelievers, since she lost her friends through their unbelief. her survival skills was on a believable level. Especially if you watched movies liked castaway & predator. Hence, she seen enough movies to cut the head off!! Go girl! Not like her skills were on a Liam Nelson "Taken " level or John Wick. But basic knowledge added with the human will & strength to survive. Didn't need an origin....I figured if there were Mermans-this would be its origin. Somethings in life, just are! Unrealistic to believe life is full of origins & closure. We have no clue what's beyond our limits of the ocean floor, that's why the black hole was critical to the story!!
Cool movie, awesome monster design, great acting, and suspense. It's hard to get me to jump....and I jumped a few times. (Clap clap clap)