Tob was Winter and Sere's son, born in the Haunted Lands after Sere's death. He was, Winter tells Jame and Tori, "slow", and his depiction in the tapestries in the master chamber of the Keep shows him as "empty-eyed".
When Jamethiel Dream-Weaver gave birth to twins in that master chamber, she had no milk; Winter was the only possible wet-nurse, since Tob had not been weaned; there was nothing suitable for a small child to eat in the Haunted Lands. Winter could not nurse three; she describes how Tob ran to Jamethiel who held him, and how Tob's soul left him in her arms. Winter then "took care of the rest."