Severus Snape, the greasy haired git. The biased Head of Slytherin House. The sallow faced Potions Master. The one person, apart from Voldemort, who seemed to hate Harry’s very existence. The Half-Blood Prince.
Throughout the series, he has remained the most mysterious anti-hero, because it was never really stated why he loathed Harry so much. And this intense dislike for the protagonist made a large number of readers hate him with utmost passion.
But he was by far one of the most interesting characters in the Harry Potter books, and in my opinion, the very best.
He makes threats, says cryptic things, and is subtly malicious for he never really shows his anger very much. When a firework explodes in his class, he calmly announces that the mischief-maker will be put in detention. Even when someone sets fire to him, he keeps his cool (no pun intended).
There is one time when he does lose his temper, though. When Sirius Black escapes from right under his – to quote the Marauder’s Map – “abnormally large nose”, he talks illogically, starts screaming and is even described as looking slightly deranged.
It might not have made much sense back then in the third book, but as the story progresses, it does fit into the jigsaw. For Snape, catching Sirius would have meant avenging Lily’s death, a small sense of comfort perhaps, that the person who supposedly betrayed their Fidelus Charm was punished.
Snape, though he hates Harry with passion, protects him throughout the series. He does it so subtly that Harry is never convinced that he is indeed not the bad guy. Even Dumbledore’s unwavering trust in Snape does little to change his opinion.
Having been a Death Eater previously, Snape is one of the very few people trusted by Voldemort. Thus he was given a most dangerous role to play by Dumbledore – a double agent. He was trusted with the task of providing the Dark Lord with information that seemed important while withholding the vital details convincingly, and in doing so, collect information on Voldemort’s next moves.
He had been the one to overhear Sybill Trelawney’s prophecy regarding the fall of the Dark Lord. But when he had learned that it meant Lily Potter’s son, his guilt, shame and anguish knew no bounds. It was enough to make him come over to the good side, and to fight alongside Dumbledore to bring down the Dark Lord.
So he protected Harry. Not because Dumbledore asked him to, not because he was possibly the one with the power to defeat Voldemort, but solely because he happened to be Lily Potter’s son.
Severus Snape did all he could to ensure Harry’s safety without letting him know so. He lied, spied, and even put his own life in danger. To look into the most evil dark wizard of all time and lie through one’s teeth was not an easy task, but he executed the task convincingly with elegance.
In the end he gave his life for the greater good, once more, for Harry – for Lily’s son.
The chapter on Snape in the last book, “The Prince’s Tale”, had one of the most touching parts in the series. When Snape casts his Patronus, it is a Doe, the same as Lily Potter’s. Dumbledore watches it bound across the grounds and turns back to him to ask, “After all this time?”
Snape’s single worded reply touched the hearts of the millions who read the books: “Always.”
All through, Snape’s allegiance lay with one person alone. Not with Voldemort, not with Dumbledore, but with Lily Potter and the love he had for her.
In the end, at King’s Cross, when his youngest son expresses his fear of being sorted into Slytherin, Harry tells him that he was named for two headmasters of Hogwarts – Albus Dumbledore and Severus Snape. One of them was a Slytherin and he was probably the bravest man he ever knew.