dreams come and go, but do we know why?

i had a dream... i lost a very good friend of mine... she was forsaken by her family and she was injured... i started from her house asking of her whereabouts. they did not know, but all there was to find her was a trail of her blood. every minute was horror. i followed the thin worn out drops of blood for hours, through the apartment. it led outdoors, through a beaten path, to a rushing lake... there were goons there... i jumped over them but landed in the water... there was a voice... it told me that i should give up. as i was heading towards a steel gate in the waterway it told me to be as straight as possible because the gate would kill me otherwise... i listened and slipped though... i went back up to the goons to follow the trail of blood. i kicked one of them in the face and continued to run behind a building and around them... i regained the blood trail.. it lead through the bush and across a cement pillar over the waterway... it lead to an abandoned house, and into that houses crawl space... i followed the blood through a very cramped passage and to a small vent... it was to small to fit in and was shut off.. i knew because the voice told me... i continued though the passage until i came back out in the main area... the blood had now crossed paths and it was hard to tell what trail led to what.... i looked down and cried... then woke up with a fever in a boiling sweat... i wanted to go back.. i wanted to find her... help her... save her... but i couldn't... it was imposable... the thought made me tear up... so i lay in my bed alone and cold..