Dream About Swimming And Enemy

I dreamed that I was like swimming or maybe standing normally on ground and there was somebody who was like my enemy maybe and whenever he was like approaching to harm me I was like jump in a river and stick beside to sth the river was like a a river falls and beside me on the right was like a complete dark and unknown thing that people don't get close to it and when the somebody sees that he just stops and don't move step closer to me as afraid to fall it happened in the dream twice