The plot sounded alright, but why only 2 people on a 4 person submarine, and he said he was going to see a friend, then never went there? Neither of them make any mention of this, after that, which makes no sense, since she had second thoughts about staying, and would insist. Why would she not question him
and demand that he do as he promised. How can she not recognize herself as a kid? Did she never look in a mirror? It seems as if they were originally going to make a completely different film, then decided, to wrap it up, as this terrible psycho rubbish, that will never be anything. The acting is also terrible. You kind of excuse it, at first, but then it just becomes annoyingly fake, as they do stuff that the intelligent characters they are supposed to be, wouldn't do. She would NEVER agree to take part in the tank, since she is portrayed as being that stubborn and headstrong. Also that woman "half warning" her, why not just blurt out the warning. That is as annoying as people who switch to slow motion during a horror movie, scared people would hurry to check what is bugging them, but then you ca't have that music and suspense buildup, however unrealistic it is. If you liked this (all these 10s ??? seriously?) there are loads of slow rubbish films for you: Check out The Connection (2021), The Pond (2021) and I Trapped the Devil (2019). They are on par with this crap.
