Ok, I have mnetioned this before but I now want to have my idea fully registered so that I cna claim the prize when I am shown to have guessed the truth about Snape.
My theory is this: Snape is Harry's father. If this were the case, it would explain how Dumbledore cna be so sure of Snape's loyalty to the Order of the Phoenix and Harry in particular. I don't go with the idea that Snape made an unbreakable vow with Dumbledore. That is too simplistic a plot-line. Snape is bound to Harry by a much deeper tie, that of being his father. It would also explain why Dumbledore said Snape was so upset when he found out who Voldemort took to mean was the chosen one in the prophecy he overheard. Of course Snape wouldn't want Voldemort trying to kill his own son!
The clues I think point to Snape being Harry's father are these:
- When Harry fell into the pensieve and saw Snape's thoughts, he was horrified that his supposed father, James, was such a prat. Later, Sirius and Lupin excused him by saying he was only 15, but Harry retorted that he was 15 and implied that he wouldn't behave in this prattish manner. So he is not so like his "father" after all.
- Snape clearly had a thing for Lily.
- Lily clearly thought James was a berk and it is not clear to harry how she could ever fall in love with James.
- The anger Snape showed towards Harry when he foudn him in the pensieve seemed disproportionate to the events Harry had witnessed. It was as if Snape was scared that Harry was going to put 2 and 2 together about something else, ie Snape and Lily's relationship. Yes Snape was being humiliated, but the overriding impression in Harry's mind was not that Snape was being humiliated (he actually said later he felt sorry for Snape) but that james was being such a prat. Why didn't Snape just say then, "See what a prat your father was?" I think he was scared and didn't want Harry delving too deeply.
How come Harry looks like James then? Well, in a way, that side of the story has been done to death - it is mentioned far too often. Even harry gets bored hearing how much he looks like James. But this is a magical world. What is to prevent someone, eiher Lily or Dumbledore, or Snape, casting some spell over Harry to make him look like James to stop the rumour that he is actually Snape's son?
Why would Lily want to do this? Why marry James? I not sure about this although it is clear that she was always on the good side and Snape dabbled with the Dark Arts so maybe she married James to protect her son. Snape's attitude to Harry is partly fueled by his inability to speak the truth to him and tell him that he is actually his father. It must be really galling to see Harry worship James and despise Snape when in fact he should be doing the reverse.
I think I have more to say on this subject, but I need to let my children on the computer now. What does anyone think of my theory?