Rachel without a doubt is one of the most believable characters in a dystopian setting I have ever read about. Since Rachel's mother died shortly after she was born and her father was the Commander's best tracker it seemed natural Rachel would grow up more a tom boyish and less girly. Not afraid to get her hands dirty Rachel has a one track mind and will do anything to get what she wants. Instead of conforming to the ridiculous cast system in place Rachel walks a dangerous line that puts not only herself in danger but everyone else she cares for.
Logan had a hard life as a child, his mother broke one of the cast systems laws and was beat to death for him leaving Logan an outcast. Ignored and treated like scum while a child Logan learned how to fight and survive. Using this to his advantage Logan convinced the Commander's best tracker to train him and thus ends his life as an outcast. Despite being proficent at defending himself Logan's real skill is inventing and technology. With Logan's quick thinking and logical mind he is a formidable opponent.
The Commander is a hard man, he keeps the city safe from the things from the wasteland and expects total obedience from anyone living in his city for that service. Unable to survive in the wastelands the citizens obey the Commander and his the strict laws of the city. Clearly the Commander is not someone who lucked into the job, he is cunning and ruthless.
Despite the characters who I all liked for one reason or another I had issues with the writing. The grammar was bad in parts and it drew my eye from the story. For that reason Defiance is not getting a five star rating.