A Diamond in My Heart, audiobook two in the Unaltered series, follows teenaged Calli Courtnae as she learns how to control her new cosmic superpowers. She's afraid she's no match for some of the other people who are showing up with different paranormal powers, including a time-rewinding teen who apparently has some romantic fantasy about her going on in his head. She faces more challenges with him as he attempts to save the day. 

Maetha, her paranormal guide, assigns Calli to investigate the young man and teach him what a real superhero looks like. Before that can happen, she'll have to determine what his power actually is - and that takes her into an action-packed adventure in itself. 

All the while, someone is systematically kidnapping the clan leaders who wear the near-magical diamond amulets. Calli feels overwhelmed with trying to figure everything out and keep balance in the world. All her powers - the ability to read minds, view the future, heal people, and locate other Sanguine Diamond Bearers - should be a good thing. They turn sour, however, when she learns of traitors who've sided with the US government, threatening her new world and the lives of those she loves. 

Even with all her superpowers, she feels alone and up against insurmountable odds. She begins to question the loyalty and friendship of others. She has no one to turn to when, ultimately, she is faced with the inevitable - the reuniting of the diamond shards. 

Who can she trust, and who just wants her dead and has everything in place to make that happen?