Children shouldn't play with dead things (слэш)

He had died, the Dark Lord had killed him. Or at least that was what he thought had happened. However, when Severus Snape awakes in a strange house under an adult Harry Potter's care, he can't be so sure of anything anymore.
Why is he even alive? and why is this grown Potter treating him with so much care and respect?
As the days go by nothing becomes clearer but quite the opposite. Something wrong is happening to his body and his feelings. But why? He would have to find the truth even if he realizes he doesn't really want to.