Because it's Friday the 13th, Christie and I are going to see that witchcraft movie tonight.
Speaking of, I've been rereading the books in preparation for next week, and I'm halfway through Goblet of Fire right now. I think I'm seeing evidence that Snape is a good guy.
All the Death Eaters (that I can think of) in the series go out of their way to be nice to Harry until such time as they 'come out', at which point they try to kill him. Even Draco kissed up to him when they first met. But Snape has been consistently contemptuous of him literally since day one. If he was a bad guy pretending to be good, wouldn't he suck up to Harry at least a little?