I'm rushing off to work, which makes me inarticulate, but oh God, this is gorgeous. Painful and physically intense and precise and so full of lost innocence and longing and the twistings of love that it brought tears to my eyes. Your use of language is wonderful; it gives me goosepimples. And you've done something few authors have managed, you've brought Lily to life for me, and I like her. Few depictions of Lily convince me, but this one does. Your young Snape is perfect, and this glimpse of the two of them together casts a retrospective - or is it forward-looking? - shimmer of what-ifs and if-onlys over their lives. They truly are friends here, and that's such a relief. Severus isn't just the pathetic hanger-on. And Harry's compulsion to merge with them, communicate with his mum, say things these children cannot possibly understand, is heartbreaking. There are many moments to love, but one of my favorites is when Snape sees Harry, the combination of Lily and James in him, and I wonder if he doesn't understand, just for that one, lost moment outside time.
Your gift for sensual detail is clearly intertwined with your ability to touch the heart of a scene, to find its bittersweetness and its absurdity. There's such a complex tension in the image of Harry kissing his mother as a way to have her with him, a way of saying everything that can't be said; and through his mother's fierce friendship with Severus, to say to him, too, what Harry would never have been capable of saying in any other way.
And then to deliberately give that up. To say good-bye. Oh, my heart.
This one enters my personal canon. Beautiful and unexpected. Thank you for this. I can't wait to re-read it.