<P> A central mystery of the series concerns Snape 's loyalties . For much of the series , Snape 's actions seem to serve Harry 's nemesis , Lord Voldemort , although Harry 's mentor , Dumbledore insists that he trusts Snape . Snape dies at the hands of Voldemort in the final chapters of the seventh book , at which time his back story is revealed : as a teenager , Snape was a close friend of Harry 's mother Lily , and he turned on Voldemort after the latter sought to kill Lily and her family . </P>
when do you find out snape is good
in the final chapters of the seventh book