I think this quote from the book expresses Alejandro (Olek) and Irena's relationship very well:
"Days will come when I will hate you Olek. But there will never come a second that I do not love you."
Irena is one tough cookie, and Alejandro absolutely loves her for that reason. An event that happened in their past has kept them willingly separated for a couple centuries. The story involves Irena working past her embarrassment and, as she comes to realize, a feeling of rejection and Alejandro his pride.
But this story is so much more. There is a revelation for Michael and much sadness for all the Guardians at the end. There is a great battle and deception from a friend. A character is forced to change and become something never imagined or wanted. I am addicted to this series. Brook writes a remarkable paranormal romance.