Last week, John Brennan, the former CIA director turned Trump-bashing talking head, predicted a final flurry of indictments from Trump-Russia special counsel Robert Mueller. The big day, Brennan said, would be Friday, March 8.

"I wouldn't be surprised if, for example, this week on Friday — not knowing anything about it— but Friday is the day the grand jury indictments come down. And this Friday is better than next Friday, because next Friday is the 15th of March, which is the ides of March," Brennan told MSNBC's Lawrence O'Donnell. "And I don't think Robert Mueller will want to have that dramatic flair of the ides of March when he is going to be delivering what I think are going to be are his indictments — the final indictments — as well the report."

March 8 came and went without new Mueller indictments, or at least new public indictments. And now comes news that Mueller's top deputy, Andrew Weissmann — also known as the special counsel's "legal pit bull" — will leave the office within the next few days.

Also, the FBI recently announced that Mueller's top investigator, David Archey, has left Mueller to take a top job with the bureau in Richmond, Va.

The departure of not one but two of Mueller's key staff — along with other aides who have moved on in recent weeks — fueled speculation that the special counsel is wrapping up his investigation. "[Weissmann's] departure is the strongest sign yet that Mueller and his team have all but concluded their work," said NPR, which first reported the news.

As always, it is dangerous to predict what Mueller will or will not do, but what are the chances that Mueller's key people are leaving while he is preparing big, new prosecutions?

"Slim and none," said former Whitewater prosecutor Sol Wisenberg in a text exchange Thursday. Wisenberg has said for some weeks now that it does not appear Mueller is planning anything new. And now comes the news about Weissmann and Archey.

"The two leaving contemporaneously adds to my pre-existing views on this based on the course of events," Wisenberg said. "If you were in their position and those big indictments were coming down, why wouldn't you stay?"

If in fact Mueller plans no more charges, the investigation would leave some key figures in the Trump-Russia affair unindicted. Besides the president himself, the two biggest are Donald Trump Jr. and Jared Kushner, the president's son and son-in-law. But the bigger picture will be that the figures Mueller did charge — Paul Manafort, Rick Gates, Michael Flynn, Roger Stone, Michael Cohen, George Papadopoulos, and others — were not charged with taking part in a conspiracy with Russia to fix the 2016 election.

Indeed, so far, Mueller, in all his so-called "speaking indictments," has not alleged that such a conspiracy existed. He has charged a lot of Russians with trying to interfere with the election, but he has not accused anyone on the Trump side of working with those or other Russians in the effort.

Had there been such a conspiracy, it seems reasonable to assume that the people Mueller charged — Manafort, Gates, Flynn, Cohen, Stone — would have been part of it, or at least would have known about it. Yet Mueller investigated and charged them all with crimes that were unrelated to the election or with lying to investigators. The special counsel has not alleged that any took part in an election conspiracy.

What seems most likely now is that Mueller will tell what he knows in a report to the attorney general. That report will almost certainly make its way to the public — on Thursday, the House voted nearly unanimously to urge its release — so Americans will finally know what Mueller discovered. Perhaps it will be a scathing assessment of what happened, a sort of nonindictment indictment of the Trump campaign. Or perhaps it will be something less.

In any event, if there are no further indictments, that will undoubtedly be a disappointment to those in the Resistance and Never Trump worlds who hoped to see people close to the president face charges.

It's always important to be modest about knowing Mueller's plans. He has surprised observers before. He might still now. But the departures of key investigators suggest that probe is reaching its end.