Does and Stags (Lily and James Fanfic)

What if Severus Snape after 13 years of still grieving of the loss of Lily Evans had finally decided to do something both cunning and dangerous that would possibly bring her back to the present (even with James and Harry to his utter distaste of course!). But with nothing and yet everything to loose from performing such an act, and if successful what will he do afterwards? Will it actually help prevent the many deaths and torture that has occurred since then? Will it save the most famous couple to survive the fateful Halloween night in which their doom was so sure? And if so what will Harry P be like with both of his parents raising him and not his horrible Aunt and Uncle?

I give my full respect to the wonderful human being which is J.K.Rowling in which all rights go to her.