This is the sci-fi short film The Secret Number.
It was written and directed by Colin Levy, based on a short story by Igor Teper, and stars Daniel Jones, Tom Nowicki, Tom Carleglio, and James Troutman. Check out the synopsis and short film below.
"Dr Tomlin is a psychiatrist. One of his patients is a former professor (Prof. Ersheim) who is convinced that there is another whole number which is meant to exist between 3 and 4. While Ersheim is sectioned and struggling to work out this number, Tomlin experiences some strange things and a memory from his youth of a car crash is triggered."
"Dr Tomlin is a psychiatrist. One of his patients is a former professor (Prof. Ersheim) who is convinced that there is another whole number which is meant to exist between 3 and 4. While Ersheim is sectioned and struggling to work out this number, Tomlin experiences some strange things and a memory from his youth of a car crash is triggered."