Shadow of the Lords by Simon Levack

Shadow of the Lords is the second book in the Aztec Murder Mysteries. Yaotl the slave is once again the protagonist and detective. This mystery begins the morning after the mystery described in Demon of the Air. Once again, Yaotl is racing against time and hiding out from reprisals from his master, the Chief Minister. This time around, Yaotl has an especially strong motivation to solve the mystery--he is trying to protect the son he discovered in Demon of the Air.

Yaotl does much of his sleuthing among the feather artisans, and considerable information about feathered adornments of the Aztecs is imparted along with the story.

This was a worthy followup to Demon of the Air, and a breakneck read.