The fifth installment of the pulse-pounding X-Ops series that RT Book Reviews says "gets better and better" 

Former Special Forces Lieutenant Jayson Harmon is still trying to come to terms with the injuries he suffered in Afghanistan that left him handicapped. His disabilities don't matter to feline shifter Layla Halliwell, but he can't understand why she'd want to saddle herself with a broken man. 

Determined to become the man she deserves, he agrees to let the Department of Covert Operations test a new hybrid serum on him. Only the serum doesn't do what the DCO claims, and when Jayson goes on a mission to the Ukraine with a partner willing to kill him if things take a turn for the worse, Layla follows, determined to keep him safe-even from himself.