Nightmare about my grandfather?

I had a dream last night, I went to my Grandparents but my grandfather was standing in the living room (the back door goes right into it) and when i went to open the door he was pushing against the door not letting me in. He then locked the door, went to his chair, light (is that the passed tense spelling?) a cigarette, reclined, started to smoke it, fell asleep, and then he and his chair suddenly engulfed in flames. What could this mean? hes still alive by the way.