Time Cut: Meets the Sine Qua Non of Paradox and Surmounting It

So, Time Cut went up yesterday on Netflix.  It's a time travel movie, so I had to see it.  The story of a younger sister who goes back in time in 2024 to prevent the murder of her older sister in 2003 by a serial killer at first seemed a little trite, even more so with the high school shenanigans in which the story is situated.  But--

The story respected the paradoxes of time travel (a sine qua non for me in a time travel narrative) -- one of the savvier characters correctly says you might stop your sister's murder and in so doing cause World War III -- and the story becomes emotionally profound when--

[And here I'll warn you about some spoilers ahead ... ]

The younger sister, Lucy, from 2024 in 2003 knows that her parents had her only because her older sister Summer was killed.  When Lucy asks her parents who in 2003 don't know they will have another child if they're planning on having another child, they tell her no, and that sounds like a fait accompli. Lucy instantly realizes that if she prevents Summer's murder, that she, Lucy, will cease to exist.

I would have liked to have heard someone in the movie -- Quinn, the teenaged science nerd, and more -- voice the new conclusion that Lucy's realization engenders: that Lucy's very existence shows that somehow it might be possible that Summer survived, and Lucy was born, anyway.  Instead, we get the emotional turmoil that Lucy goes through, wanting to save her sister, and continue living herself.

But that's ok, it all makes sense at the end, and we find out who the masked serial killer is, which I guessed, but only pretty close to its revelation in the movie.  And we even get some clever dialogue, like when Lucy tells her as yet unknowing parents after dinner, "Thanks for having me". All of which is to say, Time Cuts is eminently worth seeing.