Finn has been raised to fear the notorious Ironclads and their city, Engn. The Ironclads are sent out to the surrounding villages to recruit children to work in the city.
When the Ironclads come, there is no choice but to send the children to Engn even though few return to their homes, parents are required to let the Ironclads take what they want.
When Finn was younger, his sister was taken to Engn which was supposed to mean that Finn was safe as the Ironclads can only take one child per family. But when the Ironclads come for him, this changes everything.
With Finn on his way to Engn and almost certain death, he is reminded of a promise he made long ago–Finn and his friend Conner vowed to destroy Engn for good.
But Finn soon discovers that task is larger than originally thought. In Engn, a dictatorship runs the city and the people/workers are slaves…broken and beaten to an inch of their lives and once they are no longer useful, they are terminated.

Nerds around the world unite! This is your book!
A single choice can transform you. One choice can destroy you. On Choosing Day, the people of five different factions make a choice that will change their lives. You can choose to leave your old faction behind in favor of a new one, but you will forever be bound to your new faction so it is not a choice one makes rashly. If you fail to meet the initiation for each faction, you become Factionless.
Abnegation. Amity. Candor. Dauntless. Erudite.