It is only during the darkest of our times that we can look to happy memories to help us through them and Severus Snape is no different. Though he mostly continues on to protect the only piece of Lily that survived all those years ago, he also continues living for someone else from his past, a close friend he promised to live on for if she were to die before him. Unfortunately, that time came too soon for Severus and he is left with only his memories of her, of the other girl in his life he could not protect from the world.