Although I'm sure I've read all the elements for the de-aging and subsequent care (mixed curses, life debt etc) before, I loved the way you mixed them up to produce something new and so very in canon Snape :) I adored their interaction - I love Harry's maturity and Severus's teenaged aspects. There were a couple of Severus's reactions to some of the things Harry said that left me wondering slightly what the story was behind them, but they seemed to fit so well with your characterisation of him. And the bit where Harry woke up to a re-aged Snape nearly made me cry...Luckily the ending was lovely.