Some MacGuffins, you don't need to explain. You don't need to know what's in Marcellus' briefcase, for instance. Some MacGuffins, on the other hand, you kinda do. Or at least rationalize. The MacGuffin here is the central conceit of the movie, and the filmmakers even attempt to create a detailed scenario -- lightning strike from outer space, a blackened circle that wasn't "burnt" (it was odd that he couldn't tell that immediately from the distinct lack of a burnt vegetation smell) and two people who are apparently connected by it. The problem here is that the whole movie could easily have been made without the "death at 50 yards, woman prevents it" plot point. That's how you can tell that a MacGuffin has been misused -- when you can completely remove it and the basic plot will still be exactly the same. The only difference would be removing the "sci-fi" tag because the plot is as follows: two people wake up with no memory after a crash. They desperately seek answers. With the police on the hunt for a serial killer and his supposed accomplice, they are in a race against time to find a solution and get their memories back. They both start recovering memories, only to learn that the man is a serial killer and the woman was to be his next victim. She takes control of the situation. The man, having no empathic connection to his old self, chooses suicide over living with his curse and putting his intended victim, who he has come to love, or at least like, through any further hell. The end. The radius stuff? Achieved absolutely nothing. There might have been some metaphorical connections made, with the serial killer becoming, well, an unintentional serial killer, but the movie doesn't even dare to explore that potential point.
In itself, it wasn't a terrible movie, which is why I rated it 5 stars. But it was a deeply flawed movie because the filmmakers tried to pull a fast one on the audience -- perhaps reasoning that sci-fi is popular nowadays, and didn't trust their generic thriller to stand out without that aspect (and they were right, it doesn't stand out.) It was just deeply disappointing to get all the way to the end to discover that the sci-fi conceit was just window dressing of the cheapest sort. I don't ask for some exposition laid out for us, but I do ask that the conceit at least has some relevance and meaning.
In itself, it wasn't a terrible movie, which is why I rated it 5 stars. But it was a deeply flawed movie because the filmmakers tried to pull a fast one on the audience -- perhaps reasoning that sci-fi is popular nowadays, and didn't trust their generic thriller to stand out without that aspect (and they were right, it doesn't stand out.) It was just deeply disappointing to get all the way to the end to discover that the sci-fi conceit was just window dressing of the cheapest sort. I don't ask for some exposition laid out for us, but I do ask that the conceit at least has some relevance and meaning.