According to the book, after the first attack by the Colonies on the Republic, the Council of Twelve enacted harsh measures to prevent any further uprisings. Among these measures was a policy known as "zero tolerance," which led to the public execution of anyone caught sympathizing with the Colonies or showing any hint of rebellion.
When June Iparis, Day's mother, decided to rebel against the Republic and join the resistance, she knew the risks involved. To protect her family, she secretly sent Day and his brother John away to hide while she stayed behind. As a warning to anyone who might consider following her path, she marked her door with an "X" in bright red paint. This "X" served as a symbol of defiance, a reminder of the consequences of betrayal, and a warning to those who dared to challenge the Republic's authority.
Throughout the series, the "X" on Day's mother's door holds great symbolic value. It represents bravery, resilience, and the power of sacrifice in the face of oppression. It becomes a rallying symbol for those who resist the tyranny of the Republic, inspiring hope and encouraging others to stand up against the injustices of their society.