Mackenzie Salvador has very little in life. With a dead father and an out-of-commission mother, Mackenzie is left to run the family's mechanics shop and juggle school. Every night, she is exhausted and worn out, but the thing that makes it all worthwhile is her brother, Hunter, and best friend, Jay. When Hunter is sold by Mackenzie's mother to the Reinhardt Corporation as a test subject for the mysterious mechanical-hearts device, Mackenzie and Jay rush to the rescue. Nothing is as simple as it appears to be on the surface, and making new friendships and facing betrayal, Mackenzie must fight and persevere if she hopes to ever save her brother.