Ok, I might need a minute to scroll through my bookmarks

Edit, ok, here we go (this is just from my bookmarks and what feels most “unsettling” to me. I could sit here and link for hours to more things I have “saved” in my head, but I’ll leave it at this for now):

• List of people who disappeared mysteriously: pre-1910
  List of people who disappeared mysteriously: 1910–1990
  List of people who disappeared mysteriously: 1990–present
  Bonus addition in edit: List of people who disappeared mysteriously at sea

• Feral child

• I have quite a few pages on serial killers, but this is probably more efficient than listing individuals: List of serial killers by number of victims

• A handful of individual cases though:
  Murder of Junko Furuta
  Murder of Sylvia Likens
  Murder of James Bulger
  Murder of Shanda Sharer
  Hart family murders

• On the larger scale:
  List of genocides
  List of massacres
  Blackbirding
  Zong massacre
  Home Children
  starlight tours

• On the existential front:
  List of impact craters on Earth
  Observable universe and Cosmological horizon which make you realise that the endless and abundant expanse of space we see is only a tiny little portion of the actual universe.