Pursuing a string of murders involving corpses drained of blood, Kuroko and her hulking buddy, Urara, descend into the sewers to rescue Narumi from an all-too-familiar face. Narumi herself is determined to escape with her fellow captives, but between her broken leg and the mazelike underground tunnels, their odds of escape are grim. It's a race against the clock as the killer prepares for their next meal...