A serial killer Byung-su gets diagnosed with Alzheimer's so when a number of murders occur near the town, he worries whether the killings are his doings. Then, he comprehends he's the killer and comes across Tae-ju. He reports this to law enforcement, only to find out that Tae-ju is clearly one. Byung-su tries to find signs against Tae-ju to raise his dear daughter and the youthful killer interest on him.