I thought I knew my ending - Year 4

The voices intensified. I had arrived at a circular-shaped door that was slightly ajar. Snakes were engraved on it, and there was an inscription in a language I did not recognize, let alone was able to read.
I gripped the sword more firmly, placed my hand against the door, and pushed it further open. Not far, just enough to see what was going on behind it.
But even before I could see them, I felt the acidity rising in my throat. I braced my hand against a boulder and took a deep breath to keep it down.
Why was I so incredibly nauseous?
Probably because of the rotting smell of the decaying corpses, said the little voice in the back of my mind. Or because of the liquor that wanted to rise in my throat. Or maybe it was just because I already knew that I had made a huge mistake following her.

Book 3 - year 4 of a series about the marauders from Lily Evans POV (well, mostly).

Lily Evans gets a second change in life to change her past and therefor the future of all those around her. Unfortunately, she has forgotten what will happen to her future self. She has no idea why she has nightmares about a deer, black dog and rat or why she has all these strange memories of older versions of herself and the annoying Gryffindors she's supposed to hate. After all, being a Slytherin comes with some prejudices.
This story will take place during the marauders time at Hogwarts, all seven years and a few years after, during the war. As you will notice, I made a few alterations in this story that aren't aligned with the original one, but you will soon discover it's way more interesting to change the timeline a bit and put Lucius Malfoy and Ballatrix Black in the same school as the marauders.