Behind a series of murders involving Tsuyoshi Shimomura (Teruyuki Kagawa) that Kosaku Kuroda (Yuji Oda) is investigating, is a lawsuit over a drug called Atron, which was produced by Brighton Pharmaceuticals, an American-based company. The son of Takashige Yamaji (Ryo Iwamatsu), who attacked Rikako Ogaki (Ko Shibasaki) as she got closer to the truth, also died from the side effects of Atron.
