Wow, this is gonna be awesome.
Though i do have some kind of ideas.
For example:
.You could do a TwilightZone ending, where, after he had been curled up, he gets up and walks off slowly, (without showing his face) and he's walking down the street normally, people around him could be looking at him and screaming or running away or something, and he's still wandering what's going on, and then the guy comes up to him and asks him if he's okay, it fades to black, and you hear a scream and blood splatter, and maybe a biting sound, then go back and show your character facing the screen (Zombified) and then play the twilight zone music or something. (at this point, HAPPY HALOWEEN comes up on the screen or something.) lol
Well, all im going to say is try and keep the viewers guessing, don't make anything obvious, and don't show any of the gore/violence, it's scarier when all you hear is the sounds.
I hope i came of some sort of help.
