Go to the site help and shoot them a message letting them know about your problem. They should be able to fix it for you.
You can't email them, see them come up in search, wall comments, photo comments, tags, nothing it is like they don't exist anymore. If you've just been removed you can still see them in search and can see posts made from them from your friends profile. Just click the photo and bring up the profile and it will say add as friend.
Usually when they are black instead of blue they've changed their privacy settings so others can't see them or they've deleted their facebook all together. If you can still see them in your friend's friends list mostly likely they've changed their setting and might of deleted you. If you can't see them at all then they have deleted their facebook profiles.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.