Tracking down and starting another relationship with someone you have known over your last nine lifetimes is a serious business. Just ask Ruth, Celia's guardian angel, who wrote this. There is no time for messing around. Or is there? And you would need determination, steadfastness, fortitude, love, forgiveness you get the picture.
And this is what Celia is undertaking, but lately, especially over the last three hundred or so years, it has been getting too stressful. The trouble is she always remembers his soul, but to him, she is just a bothersome stranger. Surely, if they were meant to be together, it should be getting easier not harder. So, she has vowed to make it the last time she puts herself through this, and if it doesn't work out, she is ready to say goodbye, for ever.