Summary: After the inital win against the Magicians from Nod, Wren, Simon, Jack and others go to Nod to try to bring the Magicians and the Alchemists back together.
I tried to be pretty vague about my discriptions of A Sliver of Stardust because I do not like spoiling fiction books. But it is pretty hard to discuss a series without at least some spoilers for earlier books. In A Sliver of Stardust, teenager Wren discovers that not only is stardust capable of being used to perform magic, but that she is both able to do the magic and gifted in a rare type of magic that hasn’t been seen since there was a civil war among those who use the stardust. Users of stardust split into Magicians and Alchemists and the Magicians traveled to another planet (Nod).
The Magicians were led by a man that was defeated at the end of the first book and presumed dead. Wren at the start of the second book is still recovering from injuries and Jack, a spy from Nod whom she had saved is even worse. It appears that he is no longer able to do magic, but he is also now on the side of the Alchemists and wants to bring those who used and manipulated him to a type of justice.
Wren is called by the Ashes (magical beings) to come to Nod and work to fix the tainted stardust before it harms Earth. That starts the main story of A Legend of Starfire.
I know of Marissa Burt because of her work on a book about Christian Parenting that I found out about via twitter. I know her as a Christian pastor’s wife who is outspoken about abuse and who is theolgoically informed and who regularly writes about church politics and theology. A Sliver of Stardust and A Legend of Starfire are young adult fantasy books without any explicit faith themes. They were published by a secular press (HarperCollins) and her bio on the books doesn’t mention her faith or being a pastor’s wife. But there are subtle nods to faith here and there.