Now from your voting it seems pretty clear you want me to write about the Gospel of Mark, where it fits and who wrote it. This is the most difficult and involved project of the choices, but I accept the challenge.
The Gospel of Mark poses a unique problem for me, as there is very little unique material in the book that can be ascribed to Mark. Only a baker’s dozen verses are unique to Mark, and beyond that only a small number of phrases and some individual words. And some of this unique material is most likely part of a later Catholic layer that all books of the New Testament seem to have. As I write this I do not have the answers, and I think this will be a journey of discovery for all of us. I'll try to get the first of what will probably be a two or three part work up before the Labor Day weekend is up. No promises however.