What I think is accomplished in the very short runtime is a large amount of vague background story that is given without having to get into expositional details. The viewer doesn’t really know what Sam has done in the past and why he is the way he is, but you know something drastic has happened in his life. Sam is clearly a lonely and damaged sick young man who has sent warning signs his entire life that he would eventually become the type of man we meet at the time in which the short is set: a serial killer.
It’s also very apparent that Sam’s mother, likely out of love for her son, ignored some serious warning signs. And of course that begs to ask: what would a mother do for her son; the boy who she raised and loves so much? Sam’s open letter shows that he has reached out, but her love blinded her, forcing her into a state of denial that prevented her from stopping Sam from becoming the murderer that he has become.
Run is a fascinating, well-crafted short film that gives so much depth without having to spell things out for the audience. Instead, it give the viewer the opportunity to fill-in-the-blanks and create a backstory and a world for Sam, which makes Run worth more thought than just what is taken from the initial viewing.