Chapter Thirty-Three brings us the long-awaited truth about Snape, beginning with his childhood and stretching almost to his death. After reading his life story, we see the explanations of many of the mysteries and enigmas that have surrounded this character, and yet he remains full of intriguing contradictions.
As a child he both is and is not an appealing and likable character. We want to take his side, because he has a father who doesn’t love him and a mother who dresses him, to his humiliation, in ugly rags. Also appealing is his obvious devotion to Lily, his urgent desire to make her his friend. And yet he has already developed unattractive qualities out of his reaction to the obstacles he faces. He is secretive and closed to most people, and resentful of most of the world. He wants to be special, and wants to have a special friend in Lily, scorning her Muggle sister. And in his secretiveness and desire to be special, he is somewhat sneaky, opening Petunia’s letter and telling Lily about it.
These contradictions continue during his school years at Hogwarts, and come between him and Lily. He continues to adore her and stay loyal to her, but his contempt for the Muggles who mistreated him and his desire to be special lead him into pureblood views that are offensive to Lily, and lead him to associate with other Slytherins who see themselves as special and superior. His need to cling to Lily, which is the downside of his loyalty to her, leads him to jealously resent James Potter. He develops a mixture of bad qualities partially redeemed by his loyalty and love.
After Lily tells him that they’re no longer friends, Snape joins Voldemort and becomes a Death Eater. The one unforgivable thing he does is to tell Voldemort about Professor Trelawney’s prediction regarding the boy who can destroy Voldemort, unwittingly putting Lily Potter’s life in jeopardy. Yet Dumbledore offers him a chance to redeem himself, and Snape remains true to his promise even after Lily dies, staying faithful to her by protecting her son. Thereafter, the mixture of bad and good qualities is more a matter of surface appearance. On the surface, Snape appears to be greasy, sinister, and vindictive, but he is in reality the bravest and most reliable of Dumbledore’s supporters.