"Unsung Lord of Siyah Chan" is the first sequel to "Young Lords of Siyah Chan", which told the story of three young men growing up as ancient Maya princes.
As this book begins, the aged Lord Itzamna Balam has died, and his eldest son Yoaat must take the reins of their city-state, Siyah Chan. Yoaat Balam is uncomfortable making big decisions, or directing others - he would prefer to chart the stars or design the hieroglyphic words for inscriptions about the deeds of his ancestors.
In his new tasks, Yoaat has the assistance of his family, his two younger half-brothers Yaxuun and Kuy, his ever-faithful mother, and his three older sisters, a good thing, as it turns out, since his rule in Siyah Chan is bedeviled with challenges, and he needs all the help he can get.
To assist him in making decisions, he revamps the royal advisory council, then delegates experts to travel around the city's territory assessing the loyalty of his vassals, their ability to withstand first floods, then drought, then outright war. At home he institutes new rituals to comfort the people.
Each of his brothers has skills to offer: Yaxuun his prowess in battle and negotiation, Kuy his ability to observe and record events, and to walk the Otherworld and bring healing.
But Yoaat's brothers' mother and uncles came to Siyah Chan from faraway war-loving Chanil. The two uncles see the world differently, don't want wimpy Yoaat as Lord, and aggressively promote their worldview at every occasion, making life even more difficult at every turn, and threatening ultimately to be Yoaat's undoing.
