Updated: To correct mistake on date, see text below in red.
This summarizes the information I have seen on an excellent Twitter thread by Seth Abramson, Attorney and Professor at that University of New Hampshire.
In the Papadopoulos indictment, it says he met with Russian national to set up Kremlin channel for Trump on 3/24/2016. He told Trump about it and the ongoing DNC hack by the Russians on 3/31/2016—note the DNC did not know they were being hacked yet (hacked emails were dated from Jan 2015-May 2016). Also note that Papadopoulos is saying that EVERY attendee of the 3/31/2016 meeting lied about it. This includes Jeff Sessions, which means there is a good chance that he will face perjury charges soon.
According to J.D. Gordon, Trump campaign’s national-security policy rep for the RNC, told CNN that he and others advocated for watering down the language regarding support for Ukraine because Trump told them to do so back in March 2016–the infamous 3/31 meeting. This is a change from what Gordon said earlier this year when he said Trump had nothing to do with the change. He’s probably scared the FBI is coming after him next.
Papdopolous, per the indictment, notified Trump and others about the ongoing DNC hack in April 2016 —note the DNC did not know they were being hacked yet (hacked emails were dated from Jan 2015-May 2016). Anyway, the DNC emails were released to the world by Wikileaks on July 22, 2016.
So it seems that DNC emails in July 2016 were “quid pro quo” for Trump changing the GOP platform on 3/31/2016. Basically Trump knew the Russians wanted to collude (per Papdopoulos), that they had info that would help his campaign (also per Papdopoulos) and he took a direct act in furtherance to benefit Russia (per Gordon and others, probably Manafort once he flips, which venal guy that he is is expected, otherwise he’ll rot in Federal prison for the rest of his life). That is collusion. Mueller has Trump by short hairs and he’s just getting started with indictments.
Now let’s see what a Narcissist like Trump will do. If he fires Mueller, a crisis might occur if Congress does nothing to protect Mueller. The investigation won’t go away but Congress MUST protect Mueller in order to protect Rule of Law and the Balance of Powers. Will they do it though? I honestly don’t think they will, sadly. For the GOP in control of Congress now, staying in power seems to be more important than supporting the foundations of our democracy. Good Lord, I hope they prove me wrong and do the right thing.
No matter what though……Wow, just wow.
Sources:
https://en.wikipedia.org/wiki/2016_Democratic_National_Committee_email_leak
https://www.theguardian.com/us-news/2017/oct/30/trump-russia-indictment-george-papadopoulos
http://www.businessinsider.com/jd-gordon-trump-adviser-ukraine-rnc-2017-3
Ms. D. Ranged In AZ 
Now let’s see what a Narcissist like Trump will do.
Two possibilities present themselves immediately.
1) Donald Trump will pressure Rod Rosenstein to fire Robert Mueller for something that resembles cause. Whether or not Rosenstein does so will depend on whether he cares what his reputation will be going forward. And no, Congress will do nothing to protect Mueller or punish Trump, at least not at that point; that will happen if public opinion about the administration swings into “Worse Than Nixon” territory.
2) Trump will pardon everyone in his campaign and administration, including himself. It’s an open question whether a president can actually pardon himself—even Richard Nixon didn’t seriously consider that—but the problem is, as I understand it, anyone who’s been pardoned can no longer plead the Fifth. That means, everyone who ever worked for the Trump administration could be *ahem* interviewed by the Special Counsel and would have no way to protect themselves or Trump.
The Right is clearly worried about what happens next, since no less a personage than reliable R mouthpiece Douglas W. Kmiec has been banging the drum for months (http://www.latimes.com/opinion/op-ed/la-oe-kmiec-mueller-is-unconstitutional-20170727-story.html) that Mueller’s appointment was unconstitutional and therefore Trump is factually innocent of all accusations and Ds are a bunch of stinky boogerheads.
The next year or so should be very interesting (“Define ‘interesting.'” “Oh god, oh god, we’re all gonna die?”).
Well, let’s not forget possible state cases, which are NOT pardonable. Like in NY and all the money laundering that Manafort and Trump and Jared have all been doing or the slum lording in Maryland that Jared has been up to. In fact, I wouldn’t be surprised if Mueller hasn’t already told Manafort that if he doesn’t cooperate, that the state of NY will hammer his ass. And if it were me, I’d rather spend a few years in a nice low security federal prison than the hellholes that comprise NY state prisons until I die.