The Snails and the Attic

I had a dream the other night that I walked into an attic. It was lit by a lamp to the right of me. As soon as I walked in I saw my older sister sitting in a chair. She encouraged me to lie down on the mattress in front of her. The mattress was on the floor, no box spring, head or foot board. I had a yellow sheet bunched on top as if some one had gotten up from sleep there without making the bed. The sheet was powder yellow with small blue flowers on it. I felt hesitant to lie down on the bed as it looked like it had been there for years. I noticed a shelf system (one typically used for storage, can't remember if it was plastic or metal-leaning more towards metal) to my right as well. It had one lone card board box at the bottom shelf. The box was medium sized and I knew immediately upon looking at it that it had my old stuff in it. I walked around to the other side of the mattress instead of just lying down right when I reached the mattress. And when I laid down and glanced up there was one large snail in the bed and another on the floor next to it. There shells were colored red, white and blue with worn chalk looking paint. There was a third one to the right of me by my foot. I could sense that it was old and nearly dead. I quickly got up from the bed and I began to scream, not only because they startled me but also because I was also afraid of them, as I sensed that they were poisonous. They did not budge. When I got up from the bed I was trying to exclaim to my sister that there were large snails in the bed. She simple smirked and encouraged me to lay back down. She reassured me that it was going to be alright. I could not lie back down though. My sister and I have a great relationship in real life so i'm not sure why she'd encourage me to lay in that bed, let alone with large snails in it.