clogged toilet dream

I was at school in the bathroom except the stalls were in an extremely long line with the wall on the other side. A blank faced man wearing all black chased me with a knife down the hall-like bathroom. I hid in the last stall on top of the clogged toilet holding my breath until his black shoes came into view too close to the stall. I bursted out and ran back down out of the bathroom, ran down the hall, and to the school's main office. I locked the door and hid again behind the counter. The office has windows on nearly all sides and when I peeked from the counter, I saw him stareing at me with a phone to his ear. The phone rang in the office so I picked it up to hear him say,"If you don't come out, I'll get your family" and he ran around the corner. I screamed 'no!' and went through a wall vent nearby, crawled through it and came out into my yard. I turned around but my school had disappeared. I saw the man and started running along my long driveway faster than ever while hearing his pounding footsteps chasing me. This continued until I woke up.