The distance from the nearest star to Earth is one hundred and fifty million kilometres. As long seems to be the journey to another human being.
Rather than a story-driven plot, Latch is a portrayal of a thought process and development of thinking.
The 14-year-old main character, Henri, is being home-schooled because of his withdrawn nature. He is in a stage of his life that will very much define his attitudes towards the world and other people. He tries to seek warmth and love, but the person closest to him his father is not able to respond to his needs.
On the surface level the film is about pressure developing inside a young person's mind and what it drives him to do. On a deeper level, Latch is a portrayal of that development that will sooner or later take place in every human being.
In the end of the film the main character has traversed his own dark woods, maybe not all the way through, but the end is already in sight.