I have to admit that I wasn't really looking forward to Hawke and Sienna's book. I knew they were going to be a couple, but they didn't seem like the right fit to me. I am so glad that I was proven wrong! They were great for each other. Sienna was the perfect foil to Hawke's stubbornness. He had some hangups due to his parents' death and the death of his mate at a young age. Sienna had to work constantly to control the power of her specific ability. They've both been through a lot of pain in their past and I liked how both took the effort to make it work.
I really enjoyed the storyline involving the X designation and how far some members of the Council will go to get what they want. The love story involving Walker and Lara was a sweet touch as well.