This short film has all the elements needed to be a successful feature (maybe even a franchise) in the horror/thriller genre. A great mix of timely subtext fused with the traditional horror/thriller staples that the devout fans of this genre demand.
No spoilers here, but once you watch this you will want to see more. The production value is what you'd expect for a lower budget indie short but you hardly notice as the score and editing compliment the story perfectly to keep you engaged in the filmmakers concept.
This film is brilliantly executed by writer/director Francis Han. The cast is believable, easy to engage with, but the star of the film is Han. I highly recommend checking this out and, if you see what I see, you'll be anxious to see what Han could do with a proper budget to make 503 a feature. Well done to all of those involved.