Fisher,
I guess this is it, huh? After fourteen years together, starting a life of our own on this island, five deployments and countless letters I've written you through it all, I finally go out to the mailbox and see something I've always dreamed of: an envelope with your handwriting on it. For one moment, I actually thought you'd changed your mind, that all the awful things you said to me were just your way of coping after everything you'd been through. I was still here, Fisher. I was still here, holding my breath, waiting for you to come back even though you told me you never would. You always said you'd find your way back to me. Out of all the lies you've told me, this one hurts the most. Enclosed you will find the signed divorce papers, as requested.
I hope you find what you're looking for. I'm sorry it wasn't me.
Lucy

To get the ending they want, Lucy and Fisher will have to go back to the beginning. Through the good and the bad, they'll be reminded of why they always made their way back to each other, and why this time, one way or another, it will be the last time.