The entertainment value of this film is high. It is suspenseful and well acted. The director and actors clearly worked well together. The writers on the other hand...

The first part of this movie is amazing. Up until the main protagonists father is saved everything makes sense. If you don't think too deeply everything is fine... But really things fall apart after that. It falls apart in a slightly annoying way that makes you yell at the protagonist to use their common sense.

POSSIBLE SPOILERS AHEAD

They want us to believe that a young person in the year 2020 would not use the internet to the best of their abilities. This person doesn't have the common sense to do any research on what is happening at all. That is the biggest plot hole of this entire story.

Equally annoying is the fact that she has a zero concept of fact that changes in the past could have negative consequences on the present. She also just casually shares things about the present with this person from 20 years in the past. That's kind of rule number one of dealing with the past, is that you do not share things about the present. Especially since she wasn't doing it for a specific reason, and then already realizee that this was a horrible criminal. If only she knew when to SHUT UP!!!

Then there is this lack of memory. After her father is killed she should have remembered her mother coming to the house.