Updated on February 27 at 12:05 p.m. EST.

As of the latest indictments and plea agreements, the picture of what may have happened in the 2016 election, and the path that special counsel Robert Mueller is on, are becoming clearer. Washington is impressed with the airtight secrecy of Mueller’s operation—showing that this is possible among professionals who aren’t playing party games.

For example, the announcement on Feb. 16 of the indictment of thirteen Russian individuals and companies came as a bolt from the blue. This could probably be explained by the absence of lawyers for the Russians—unlike those for the Americans whom Mueller wants to talk to, who can be seen coming and going from the federal courthouse and are the sources for most of the stories about the special counsel’s investigation. Consider the contrast with Capitol Hill, where appearances before even closed sessions of the intelligence committees—especially on the House side—leak like the veritable sieve. (This may well explain why Stephen Bannon only appeared before the House intelligence committee under a broad interpretation of immunity, but has talked at some length to the prosecutors. Bannon knows well that his testimony would quickly be reported to the White House by one of its stooges on the committee.)

The picture of the Russia investigation has been filled out by the further indictments last week of former Trump campaign chair Paul Manafort and his former top assistant Rick Gates, who then decided to cooperate with the special counsel. As Maggie Haberman of The New York Times has pointed out, the significance of this is not just what Gates can tell prosecutors about Manafort. In Manafort’s testy public statement about Gates’s decision to flip, he made it clear that he’s worried about what Gates might tell the prosecutors about him. But Gates had stayed with the Trump team after Manafort was fired in August of 2016, remaining during the transition and then working for a Trump PAC, with access to the White House. That makes it highly likely he has plenty of material of interest to the prosecutors about Trump himself. Otherwise the terms of Gates’s deal with the counsel wouldn’t have been so lenient. (Mueller has since moved to have all charges against Gates dropped.)

When Manafort joined the Trump campaign as manager of convention activities in March of 2016 (he was named full campaign chairman in May), Trump either was impressed with a man apparently wealthy enough to offer to work for no pay (though as it happened Manafort was at the time deeply in debt to a Russian oligarch) or, just possibly, had been encouraged, directly or indirectly, by Russians or their American contacts to take him aboard. What the indictments make clear is that once Manafort was in charge of the campaign various attempts were made by Russian figures to infiltrate it. This could of course be coincidental. But at the least one must ask why Manafort, who was beyond broke, offered to manage the campaign of a then-unlikely Republican presidential candidate, one who’d been spurned by almost all of the Republican establishment.