Robert Mueller’s indictment of 12 Russian military officers for hacking the Democratic National Committee’s computers was a stunningly difficult feat of counter-intelligence and criminal investigation. The document’s 29 pages were filled with granular details about the clandestine, overseas 2016 election-interference operation. Yet the indictment’s greatest significance may be buried in the facts that Mueller underplayed, and in the possible conspirators—Americans—whose identities the special counsel only teased.

“The thing that this indictment completely changes is it says that the hacking conspiracy wasn’t complete before all of these communications between Russians and Americans took place,” says Susan Hennessey, the executive editor of the blog Lawfare. “It was ongoing, even after WikiLeaks released the D.N.C. material in July 2016. It endured in the period in which we know members of the Trump campaign were communicating with indicted conspirators about the topic of the conspiracy. Whether or not we’re talking about Donald Trump Jr. or someone on the periphery, we still have a lot of missing pieces. But it pretty dramatically increases the possibility that someone actually did cross the line.”

Trump Jr. and his dad’s presidential campaign have denied trafficking in stolen Democratic e-mails. The special counsel keeps chipping away, though. “Mueller’s work says these Russian guys were in touch with Americans all over the place,” one congressional investigator says. “And there is a point in the 2016 timeline, after which, if you talked to these people—whether or not you believed they were Russian agents—and said, ‘Hey, I love what WikiLeaks is putting out there. Can you give me some more?,’ you are soliciting goods that you know to be stolen. And that’s a crime.”

Mueller’s indictment makes reference to five Americans who were in touch with the Russians through Guccifer 2.0, the hackers’ online front. Two of those individuals have essentially raised their hands: Roger Stone, the gleeful political dirty trickster and longtime Trump adviser, and Lee Stranahan, a reporter for Breitbart News and then Sputnik, a Russian government-controlled media outlet. Both have denied knowing that Guccifer was peddling stolen e-mails. The Smoking Gun, an investigative-journalism Web site, also volunteered that it is the “reporter” who Mueller says was offered stolen e-mails by Guccifer. Mueller describes a fourth American as a “state lobbyist and online source of political news,” who received 2.5 gigs of stolen Democratic data from Guccifer. That fits with the profile of Aaron Nevins, a Florida Republican operative who blogged under the pen name Mark Miewurd (get it?), and who has claimed he was acting as a journalist in seeking out the hacked e-mails.

The fifth and murkiest American, “a candidate for U.S. Congress,” sought and obtained damaging information on his or her opponent, according to Mueller. Speculation has centered on four Florida Republicans: Carlos Curbelo, Brian Mast, Matt Gaetz, and Ron DeSantis. Democrat opponents of each had to contend with the public release of hacked internal campaign information; all four won their races, and all four have denied any link to Guccifer. (DeSantis has called for an end to Mueller’s investigation, and Gaetz introduced a resolution calling for the impeachment of Deputy Attorney General Rod Rosenstein.)

“Mueller’s most recent work—in combination with the charges against Maria Butina, which refer to two Americans—certainly tells the story of American involvement in the Russian election interference,” says Jim Himes, a Connecticut Democrat who sits on the House Intelligence Committee. “That adds to the story we already know: we know the George Papadopoulos story, we know the Don Jr. story. And Michael Cohen is alleging that the president was aware of the Don Jr. Trump Tower meeting. So the question at this point is really—is this whole incredible cast of characters guilty of something other than extraordinarily bad judgment? I’m as close to this as anyone who’s not on Mueller’s team, and I would say it’s still quite hard to tell.”