When Gideon Biddle discovers that he has the power to walk through shadows into a parallel world called the Midlands, he finds himself lost in a strange world where magic still exists, people race dragons, and where being human is against the law. Pursued by the MRA (Middling Relations Agency) on Earth for being a traitor and a spy and wanted for murder and intent to cause war in the Midlands, Gideon is befriended by a dragon rider, Emily Teague, and a Renegade Wizard, Griffin Nightshadow. Together this unlikely trio must race to find the Sword of Rosinell before the dragons of the Midlands can destroy the rift separating the two worlds. A quest to not only save the Midlands but his own world as well. Gideon Shadowwalk is a true hero's story where greatness is not born but is chosen.

The edge of darkness is where revenge begins. In the darkness of night, a frightening new enemy has emerged to threaten the safety of the two worlds. Gideon Biddle, the boy who can walk through shadows, returns to the magical world of the Midlands in order to save Griffin Nightshadow from his Drack mentor, Ign Creech. Facing the dangers of wild magic, Gideon must delve into the past of Griffin and Zephren Raginall in order to stop the terrifying Ambient Army from conquering the Midlands once and for all.

Spending his vacation in a boarding school where students vanish from all records and memories isn't Gideon's ideal plan for summer break, but as a fledgling agent for the Shadow Knights, his first assignment is to discover why. Gideon Biddle is a fourteen-year-old boy living with one foot in the world of Humans and the other in a world of magic. Having no magical abilities, the Shadow Knights recruited Gideon because of his past heroic acts. Unfortunately, Gideon cannot remember any of the events that earned him the title Sir Biddle, Knight of the Shadows. Gideon's goal to find security and stability ends as his first mission sends him to a private school for Middlings and Humans severing the thin thread of family he had with his foster parents the Simples. A longstanding rivalry draws Gideon into a dangerous game with deadly results. Unless Gideon can unlock the secrets of Fallenbridge Academy, a malevolent secret hidden in the school's past will be released, destroying magic forever.