I've been looking around and can't find this. I'm running a one-shot CoC 6e tonight. I was planning on running The Edge of Darkness, which is in the main rule book, but just found out some of my players have played all of the scenarios from the 5e book. Anyone have one around they can check?
Yeah, that adventure is in there
I don't have the book handy, but that mission does appear in 5th Edition Call of Cthulhu.
I've run it before, and additionally the top of this PDF indicates it was printed there: http://www.pelgranepress.com/trail/files/conversions/Edge%20of%20Darkness.pdf