This book is a sequel to "Shadow and Bone" and was published in 2013.
In the second part, Darkling takes Mal and Alina hostage. Mal is made to find the Sea Whip as an amplifier for Alina. However, the prince of Ravka, Nikolai, helps them escape. But in the end, Darkling attacks the palace and seizes the throne, and Alina runs away.
Most of all, I remember the moment when Alina tries to kill herself using her connection to Darkling. This book has taught me that sometimes you have to make great sacrifices.