Mueller has impaneled a grand jury, and issued subpeonas relating to the Don Jnr meeting.
Two bipartisan bills that make it much harder to remove a Special Counsel, and thus restrict Trump’s ability to fire Mueller, have been introduced to the Senate. I think that is the inevitable result of someone like Trump who has no respect for the importance of democratic behavioral norms, that in his wake we’ll find a few norms have become hard laws that can’t be stepped around.
Trump’s government is in the middle of a contractual dispute with Trump’s companies i.e. The Secret Service have moved out of Trump Tower and onto the sidewalk in front of Trump Tower for the moment as Trump Tower want to charge too much for an appropriate space.