[SPOILERS] I need some help guys.

So after killing Yhorn the Giant, I was teleported somewhere and put a goblet on an alter. All of the sudden a boss climbs in, and I fucking homeward boned my way outta there because I wanted to save my 100k souls. Where the fuck was I? I realize now that it was probably important for me to finish that fight to progress the story, but I don't know where I was. I'm assuming since I was supposed to save Prince Lothric's soul that I was somewhere in Lothric.

Thanks in advance.