Reed and Mayer’s excellent eighth John the Chamberlain mystery (after 2008’s Seven for a Secret
) centers on the real-life Nika riots, which nearly destroyed Constantinople in A.D. 532. When two prisoners escape police custody, each a member of “the two main factions who supported the opposing chariot teams at the races in the Hippodrome,” Emperor Justinian sends John, his trusted chamberlain, to investigate. John soon finds the young men’s bodies in the chilly waters of a cistern. Meanwhile, two nephews of a former ruler may provide a rallying point for General Belisarius should he opt to stage a coup as rival political factions wreak havoc throughout the city. Subtle, well-drawn characters, from the ascetic John to the capricious and enigmatic Justinian; deft descriptive detail revealing life in the late Roman Empire; and sharp dialogue make this another winner in this outstanding historical series. (Apr.)