https://www.youtube.com/watch?v=4Y7LpMraIncYou know in retrospect this scene really opens up more on rewatch. Considering the ending. Who really was the mystery man and how was he in both places at the same time? What was the implication of him only being where he's invited? At first I was thinking he's a vampire or something, but I feel like he's probably a more spiritual being. In defiance of the concept of space and time, it feels like he exists above the meta of the story being a weird sort of loop. I think he represents the malevolence of Fred after finding out about his wife's infidelity and that's why he says that Fred invited him, and why at the end when Fred's taking out Dick he's tagging along despite supposedly having been working for Dick in the Pete fiction. They
have met before at Fred's house. Where he loses himself in rage and kills his wife for her infidelity.
Although it only makes sense when you understand the motivation behind the killing why it happened. The Fred in the beginning is not the Fred that went through all that and found out about the cheating, or is he? How long has that loop been going on and where did it start? It seems like with the opening, it starts off just how it ends with the highway chase (though it's not shown to be the chase at the start).