This is another Harry Potter and the Deathly Hallows SPOLIER. Don't say I didn't warn you.
I've always known from book 1, Harry Potter and the Sorcerer's Stone, that there is something more to Severus Snape other than his hatred for James Potter. He was an enigma since. By the 6th book, I had a hunch that he was Dumbledore's mole. In the 7th and last installment, I was surprised to know his motivtaion to succumb into Dumbledore's plans and orders.
And I thought that Remus Lupin's character was so romantic.
Snape was the uber lover of Lily Evans. Sadly, his pasison for the Dark Arts cost him his own loss. But then, Lily's son lived. Redemption came seventeen years after.