The mind is the most unknown and sometimes the scariest place in the world if it finds its way into the darkness. How long does it take for a human being to give up mercy and kindness and what he was before and think only of himself? Do blackness and misery come from the labyrinthine corridors of the mind or are they inherited? How much do those around us and society play a role in changing our personality and way of life? The Sinkhole confronts the audience’s mind with such questions by telling the story of a lonely girl who finds herself in a morally complicated situation. Monireh came from a small town with honest people and simple issues to Tehran to study for her doctorate and now lives with her aunt's family. The Aunt's family members each have their own problems; Like addiction and depression. Monireh starts to work in a boutique to support herself. But due to a fund deficit and a mistake in her calculation, she owes money to her employer. She has to sort out the money anyway. Monireh is so worried about this that she becomes sleepless and thinks of selling her laptop. But it may be an easier way. For example, emptying the bank account of a beggar for whom she took money from an ATM some time ago. Monireh must decide on this dilemma. Is she allowed to submit to the darkness? How dark is the mind supposed to be, and turns a human being into another creature?