I became addicted to YA fantasy over the summer holidays and discovered Holly Black after reading The Cruel Prince, which I loved. The Lost Sisters is a companion novella to The Cruel Prince, so you really need to have read that one first to appreciate it.
Jude and Taryn are twin sisters, of human parents, who have ended up living in the world of the fae after being kidnapped by their step-father. Both have very different tactics to survive this strange new world, tactics that are often in conflict with their sister's. Both crave respect from the fae; is power a way to achieve this?
As this is a novella, it's hard to say more about the story without giving away the plot. So I'll just say that whereas The Cruel Prince was from Jude's point of view, this story gives Taryn's version of events.
I did enjoy it but this is really one for existing fans of the series - something to keep us going until the next book in the series, The Wicked King, comes out in January 2019. If you can't wait that long, Holly Black's other books - Tithe and Ironside - are set in the same world and some of the characters reappear in The Cruel Prince.