Disappointingly predictable. 🙄 you know what WOULD have been cool? Start in the present time (2024) with SUMMER, show her amazing & successful life. Then have something subtle happen where she just dissappears while simultaneously LUCY wakes up in her bed with amnesia. (Show her drifting through a day confused & disoriented - fill time) cue some odd flash backs or dreams of her life. Finding the time machine, figures it out, travels back & tries to save her sister. Discovers who the killer is, takes the time machine back to the future before the killer goes back, destroys the time machine then sets up the killer who goes to prison thus unable to travel & saving everyone. But in the end she disappears. Cut back to the past where Summer is none the wiser and show her parents telling her they're pregnant. They celebrate at olive garden. Finish it in the future with summers perfect life & Lucy walks into the scene. The end.