To investigate her mother's murder, Seraphina Shaw, the Saintess of the Southern Reaches, returns to Veridia with her son, Leo. She reunites with Leo's biological father, Alaric Morgan. They join forces to navigate court power struggles and a Gu poison crisis, foiling a conspiracy by the Grand Sorcerer to wage war for personal gain. As they work, they realize their feelings and, after stabilizing the court, journey to the Southern Reaches.