Trials of Conviction - The Firebird Chronicles, #5

Her niece-taken. Her best friend-gone. There's only one mission that matters now-rescuing her loved ones from enemy hands. Forced to embark on a dangerous journey, Kira will need every one of her allies as she prepares for the greatest battle of her life. With her mind and body failing, it's a race against time to locate the homeworld of the Tsavitee. The alien race intent on dominating the universe.
A shadowy force stalks her every move. Their motives unclear. As secrets come to light and the danger deepens, the Phoenix will be forced to rise. One thing is clear-not everyone will make it out of this unbroken. The price for failure has never been so high.