Memento meets Dexter which at times reminds of The Wailing and Insomnia. Byung-Su is a former serial killer who is living with his daughter and has got Alzheimer's disease. When new killings start to happen he suspects a young police inspector to be the culprit but not sure if he himself has been doing the murders and forgetting it. Sul Kyoung-Gu gives an incredible performance as Byung-Su and carries the whole film. The film keeps the audience guessing what's actually happening, a bit too much. The effect of domestic violence and relationships are touched upon. The mysterious mood is kept throughout the film which was effective in engaging the audience.