I think that the theme of the story is change because the main character (Matt) will try and change everything wrong with enslaving clones He first decide to change things on  how they where not treating the clones the same way when he sees how they where being treated."He would tell them when to rest,when to drink water,and when to start work again."This shows us he dint like the way they where being treated.He resolves this issue later on in the book when he says"Cienfuegos says he can organize the Farm Patrol into a decent police force, and sor Artemesia will try to look after people's souls.Our old,predictable lives are going to change."This shows us that he is doing something that will make it so that the farm slaves will be treated better and be given more freedom.There are several more examples on how he changed the country but I think this was the main one he was focused on and is also why I think the theme of the book is change.