Mistress of Cats - Legends of Tirum, #4

Phoenix Telyn Gwndal swore to return her friend and blood sister to her proper place within the Imperial Palace of Targoth. She knows the risks of even showing her face inside the Empire's borders, but she owes Reaphia a second chance. When a chance encounter with an out-of-place merchant from a legendary people brings Telyn into the middle of a sruggle to free a woman held captive by her own will, Telyn finds herself up against a past she's never really outrun.  Nothing can prepare her for what comes next.