Newly reinstated to the Homicide Division and transferred to a precinct in Tokyo, Inspector Iwata is facing superiors who don't want him there and is assigned a recalcitrant partner, Noriko Sakai, who'd rather work with anyone else. After the previous detective working the case killed himself, Iwata and Sakai are assigned to investigate the slaughter of an entire family, a brutal murder with no clear motive or killer. At the crime scene, they find puzzling ritualistic details. Black smudges. A strange incense smell. And a symbol--a large black sun. Iwata doesn't know what the symbol means but he knows what the killer means by it: I am here. I am not finished. As Iwata investigates, it becomes clear that these murders by the Black Sun Killer are not the first, nor the last attached to that symbol. As he tries to track down the history of black sun symbol, puzzle out the motive for the crime, and connect this to other murders, Iwata finds himself racing another clock--the superiors who are trying to have him removed for good. Haunted by his own past, his inability to sleep, and a song, 'Blue Light Yokohama,' Iwata knows time is running out.