Three years ago, Choi Moo Gak was mysteriously entangled in the "Barcode" murder case, resulting in not only the death of his sister, but also in the loss of most of his senses. While unearthing the cold case, Moo Gak crosses paths with Oh Cho Rim, a fellow victim who gained the synesthetic ability to see smells, but lost all of her memories prior to the incident. Moo Gak and Cho Rim combine their strange powers to track down the culprit, but are they ready to confront the truth?