very disturbing dream!! Help!

I had a dream that me and my brother and my brothers friend and some of our other friends where going somewhere and we where all in this huge room togther then my brothers firend Billy gets really mad and storms out of the room and my brother goes after him and of course i follow we where just sitting outside and we hear shuffling in the bushes but then though it was a cat or something then like 5 minutes later we heard footprints but there was no one in sight soo my brother goes inside and i follow him after awhile billy never came back soo i looked out side and there was a ghost behind him and i screamd *Bily watch out* but i was to late the ghost touched him and he fell to his death i screamed and fell to the floor crying and tring to tell someone what just happened but all i could do was cry until my brother looks out but then i woke up............ could someone tell me what this disturbing dream meant?

ummm didnt go back to sleep that night