Aria H. Kanzaki and Kinji Tohyama are Butei-armed detectives-and are hot on the trail of the Butei Killer! Having foiled the Killer's attempt to hijack a bus, both Kinji and Aria assumed that the case and their one-time partnership were over. However, an unexpected guest is awaiting Aria on her plane back to London. Can Aria and Kinji finally bring the case and their unsettled feelings to a close? Find out in this volume of Aria: The Scarlet Ammo!