What a unique way to get them together. Not time travel, not deaging. The way you pulled Harry between the two worlds and between Snape and his friends.
This is so well-written, the images linger with me after reading, and I know that I want to read this again and again. And you've left me with questions about the Harry who is yet to be born, and the impact of Harry's decision on the timeline. I do so like a story that makes me think.