A Prison Tale 

A really wonderful story. I loved the explanation as to why Severus can cast a Patronus charm unlike the other Death-Eaters. LOVE. Loving Lily was his only happy memory. I found great Vil's explanation about her presence, what she is, what she does, and patroni in general.

Severus' meetings with his various selves in the future (one obviously over Dumbledore's grave, when he has to protect the students while Hogwarts Headmaster) present him with the choices he can make. All his choices, starting with saving Lily and James, shows that he is deeply GOOD, deep down his heart. But we all knew that already ;-)

I found the characters credible with themselves (agh James...) while providing a possible entry point for an alternate timeline for Severus' destiny and ultimate fate. A fate in which he would not die, for example.