bad nightmare last night

unfortunately, last night I had a nightmare. I was in a house, and suddenly a large pile of black liquid smashed through the ceiling and landed in the corner.

there was a girl sitting at the kitchen table studying, and wearing headphones so she didn't hear me cry out. she did look up, and seeing the blob, went to check it out.

She got too close, fell in, and tried swimming towards me, crying for her mother.

But she couldn't reach me, and she drowned.

I'm still very shaken by this.