Thank you, I'm so glad you enjoyed it! I've written Snape many times before, but I've never tried tackling Aberforth, and he was a pleasure to puzzle out.
This fic is all about missed opportunities, but considering that neither of them sees the whole picture - and that the shadow of Albus in the background keeps falling between them - it would be asking a lot for Severus and Aberforth to trust each other. And in the end, of course, circumstances conspire against them.