So I'm rewatching Game of Thrones

[Soubriquet]

One of the perks of having the dvd's and I've just started season 3

Why don't the white walkers kill Sam when he is hiding behind that rock?

They see him but walk away. Why?

Its been ages since I watched it, but isn't it because he's holding the dragon glass? It comes up later on as a way of defeating the white walkers.

Yeah the dragon glass saves him. Me and dh watched series 1-4 before Xmas!! All in December and never went to sleep before 1pm!!! Addictive definitely!!