Also, just published was a transcript of a recorded conversation between Papadopoulos and a confidential human source. I saw some other article that claimed that the confidential human source was Halper.
I believe that the keys to this conspiracy are, among others, the people who attempted to incriminate Papadopoulos. That would include Halper, Misfud, Tawil, and Downer. The more we hear about Papadopoulos, the more likely I think it is that the investigation will succeed and I suspect that Brennan's name will come up.
If we get some action on this before the election and after this crisis has peaked then the timing would actually be perfect, since if we had gotten results before the pandemic then people wouldve forgotten about it by now.