After one year, 10 months, and six days, Special Counsel Robert Mueller has submitted his final report to the attorney general, signaling the end of his investigation into a potential conspiracy between President Donald Trump’s campaign and Russia.

Mueller’s pace has been breakneck, legal experts tell me—especially for a complicated criminal investigation that involves foreign nationals and the Kremlin, an adversarial government. The next-shortest special-counsel inquiry was the three-and-a-half-year investigation of the Plame affair, under President George W. Bush; the longest looked into the Iran-Contra scandal, under President Ronald Reagan, which lasted nearly seven years. Still, former FBI agents have expressed surprise that Mueller ended his probe without ever personally interviewing its central target: Donald Trump.

The content of the special counsel’s report is still unknown—Mueller delivered it to Attorney General William Barr on Friday, and now it’s up to Barr to write his own summary of the findings, which will then go to Congress.

While aspects of the central pieces of Mueller’s investigation—conspiracy, obstruction of justice, and kompromat, the Russians’ practice of collecting damaging information about public figures to blackmail them with—have been revealed publicly through indictments and press-friendly witnesses, the legitimacy of Trump’s presidency, and Mueller’s own legacy, still hang in the balance. Did Trump’s campaign knowingly work with Russia to undermine Hillary Clinton and win the election? And how much was Mueller actually able to uncover?

Here are the threads Mueller has begun to publicly unravel—and the lingering mysteries that might fall to Congress to solve.

Conspiracy

To date, Mueller has leveled the conspiracy charges most relevant to the core of his probe—Russia’s election interference—at Russian nationals. In February 2018, his office indicted 13 Russians connected to Russia’s Internet Research Agency, a troll farm based in St. Petersburg that flooded the internet with propaganda and divisive political content leading up to the election. Beginning in 2014, Mueller wrote, the defendants “knowingly and intentionally conspired with each other … to defraud the United States” by influencing U.S. political processes in an operation they dubbed “Project Lakhta.” Two of the defendants, Aleksandra Krylova and Anna Bogacheva, actually traveled to the United States in the summer of 2014 to “gather intelligence” for the project, according to the indictment. The indictment did not make a judgment as to whether the results of the election were impacted, or whether collusion between the Trump campaign and Russia occurred.

Months later, and just days before Trump’s bilateral summit with Russian President Vladimir Putin in Helsinki, Finland, Mueller pounced again: He indicted 12 Russian military-intelligence officers, alleging that they had hacked the Democratic National Committee, the Democratic Congressional Campaign Committee, and top staffers for Hillary Clinton’s campaign. (The entire contents of the Clinton campaign chairman John Podesta’s email inbox, stolen by Russia in March 2016, were dumped by WikiLeaks just minutes after the Access Hollywood tape damaging to Trump was released by The Washington Post.)

Again, though, Mueller stopped short of alleging any kind of coordination between the Trump campaign and Russia. The closest he came was this sentence: “On or about July 27, 2016, the Conspirators attempted after hours to spearphish for the first time email accounts at a domain hosted by a third-party provider and used by Clinton’s personal office” (emphasis mine). By using the words for the first time, Mueller appeared to be emphasizing the fact that the hackers’ activity that day was unique—a significant detail, given another major event that took place on July 27, 2016: Trump’s “Russia, if you’re listening,” speech, in which he implored Moscow to find Clinton’s emails.

The closest Mueller has publicly come so far to establishing a link between Trump’s campaign and the Russian hackers is through Roger Stone, a longtime Trump confidant whom Mueller charged in January with obstruction of justice, making false statements to Congress, and witness tampering. In a court filing last month, Mueller linked Stone directly to one of the Russian military-intelligence (GRU) officers, writing that the search warrants his team conducted against the GRU revealed that Guccifer 2.0, a fictitious online persona created by the Russians, “interacted directly with Stone concerning other stolen materials posted separately online.” Stone has said he had “a short and innocuous Direct Message Exchange with Guccifer 2.0” in August 2016, in which Guccifer offered to “help” him. The January indictment of Stone also offered the clearest link yet between the Trump campaign and WikiLeaks, and suggested that the campaign might have known about additional stolen emails before they were released.

Many questions are still unanswered. One of them is whether Stone and the Trump campaign coordinated WikiLeaks’ release of the stolen Podesta emails to distract from the Access Hollywood tape, which showed Trump making vulgar comments about women. The emails were dumped just minutes after the tape was released on October 7, 2016, and the Stone indictment reveals a tantalizing new detail: Shortly after the Podesta emails were released, a Trump-campaign associate texted Stone “Well done.”

Also unknown: the whereabouts of a Russia-linked professor from Malta who told the Trump-campaign adviser George Papadopoulos in April 2016—before the Russian hacks were made public—that Russia had “dirt” on Clinton in the “form of thousands of emails,” according to a criminal information filed by Mueller against Papadopoulos in October 2017. It is still not clear how the professor, Joseph Mifsud, seemed to know in advance that Russia sought to compromise Clinton’s candidacy, and he has virtually disappeared since his name was made public in 2017.

And what about the internal campaign polling data that Trump’s campaign chairman Paul Manafort gave to the suspected Russian agent Konstantin Kilimnik in August 2016? One of the top prosecutors on Mueller’s team, Andrew Weissmann, said in a closed-door hearing last month that this episode goes “very much to the heart of what the special counsel’s office is investigating.” But it has yet to be resolved in either court filings or hearings in Manafort’s case—he was sentenced last week to serve about seven years in prison for tax and bank fraud and failing to register as a foreign agent for Ukraine.

The extent to which Manafort was using his high-level campaign role to curry favor with the Russian oligarch Oleg Deripaska is also still unclear, as is the purpose of a meeting that another Russian oligarch, Viktor Vekselberg, had with Trump’s former lawyer Michael Cohen before the inauguration. A meeting that Trump’s son-in-law and senior adviser, Jared Kushner, had with Russian Ambassador Sergey Kislyak in December 2016, in which Kushner proposed setting up a secret back-channel line of communication to Moscow using the Russian embassy, has also never been fully explained. Nor has Kushner’s meeting around the same time with Sergey Gorkov, the CEO of the Russian state-owned Vnesheconombank and a close friend of Putin’s. The meeting came as Kushner was trying to find investors for a Fifth Avenue office building in Manhattan. (Reuters reported in 2017 that the FBI was examining whether Gorkov suggested to Kushner that Russian banks could finance Trump associates’ business ventures if U.S. sanctions on Russia were lifted or relaxed.) The Kremlin and the White House have provided conflicting explanations for why Kushner met privately with Gorkov in the first place.

A 2017 meeting in the Seychelles involving the informal Trump-campaign adviser Erik Prince and another Russian banker also remains a mystery, as does a proposed peace plan for Ukraine that Cohen delivered to the White House in January 2017, which would involve lifting sanctions on Russia. Former National Security Adviser Michael Flynn’s motivations for lying to the FBI about his conversations with Kislyak about sanctions—a felony to which he pleaded guilty in December 2017—are similarly unclear. (Flynn has been cooperating with Mueller for more than a year.) Just days after Trump took office, though, his administration looked into lifting the sanctions that former President Barack Obama had imposed on Russia over its meddling in the 2016 election, raising questions about whether some kind of quid pro quo had occurred.

Obstruction of Justice

Much has been reported about the special counsel’s interest in whether Trump obstructed justice—a felony—when he asked former FBI Director James Comey to drop the investigation into Flynn in February 2017; fired Comey in May 2017; and, in July 2017, drafted a misleading statement about a meeting his campaign had with Russians at the height of the election. But Mueller has revealed virtually nothing about that line of inquiry in court filings, perhaps out of sensitivity to the Justice Department policy that forbids the indictment of a sitting president. Whether he addresses it in his final report is an open question.

Even so, we already know a lot about what Mueller has been interested in. According to The New York Times, Mueller has been examining how far Trump went to keep Flynn in his orbit and safe from prosecution after the White House learned that the FBI was examining Flynn’s phone calls with Kislyak during the transition period. Mueller has also been investigating Trump’s decision to fire Comey a few months after asking him, unsuccessfully, for both his loyalty and to let Flynn “go.” Mueller is also reportedly interested in why Trump was so angry with then–Attorney General Jeff Sessions for recusing himself from the Russia probe, and wants to know more about Trump’s attempts to fire him after he was appointed—attempts that were reportedly thwarted by the president’s staff.

Despite Trump’s claim that Comey was fired because of how he handled the Clinton-email probe, Trump reportedly told Kislyak and Russian Foreign Minister Sergey Lavrov that firing Comey, whom he described as a “nut job,” had eased the pressure of the ongoing Russia investigation. “I just fired the head of the FBI,” Trump told the Russians, according to a document summarizing the meeting that was read to the Times. “I faced great pressure because of Russia. That’s taken off.”

After Comey’s firing, the FBI opened a counterintelligence investigation into the president himself—an unprecedented move—to determine whether he was acting as a secret Russian agent. The obstruction inquiry was folded into that broader counterintelligence probe, according to the acting FBI director at the time, Andrew McCabe. Mueller took over the entire Russia investigation, including the counterintelligence probe into the president, days later. The question the FBI was trying to answer—whether Trump was acting at Russia’s behest rather than in U.S. interests—remains an open one.

And then there’s the infamous Trump Tower meeting with the Russians at the height of the election—and the misleading statement that followed. In July 2017, as Trump and his aides were flying back to the U.S. from a whirlwind trip to Poland and Germany, The New York Times published what seemed like a smoking gun: Donald Trump Jr., Paul Manafort, and Jared Kushner had attended a meeting at Trump Tower on June 9, 2016, with a Russian lawyer who promised dirt on Clinton. When news of the meeting broke, Trump—who has insisted that he did not know about the meeting until it was reported in the Times—helped write a statement for his son that omitted any reference to compromising information about Clinton; it said the meeting was instead about Russia’s adoption policy, a topic the president had discussed the day before with Putin at the G20 Summit. Mueller has made that misleading statement a focus of his investigation, according to questions drafted by the president’s lawyers based on their conversations with Mueller’s team.

Kompromat

The House Intelligence Committee, led by Democratic Congressman Adam Schiff, is now fixated on investigating one overarching question: Is the president currently compromised by Russia? Mueller has not publicly drawn any conclusions about how Trump’s business dealings or personal behavior might have made him vulnerable to blackmail before—and perhaps even during—his time in office. But in charges filed last year against Cohen, Mueller provided the public with evidence, for the first time, that could show that Trump was compromised by Russia while Putin was waging a direct attack on the 2016 election.

Cohen admitted in federal court in New York in November that he lied to Congress about how often he and Trump had spoken about building a Trump Tower in Moscow in 2016, and acknowledged that he had tried to organize a trip for Trump to Russia in 2016 to scope out the potential project after Trump clinched the Republican nomination. He lied both to minimize Trump’s link to the Moscow project and to limit “the ongoing Russia investigations,” according to Mueller’s team. Cohen, who sat for more than 70 hours of interviews with Mueller’s team last year after deciding to cooperate, also contacted the Kremlin “asking for assistance in connection with the Moscow Project” in January 2016, according to Mueller. Cohen was sentenced in December to serve three years in prison for tax and bank-fraud crimes and making false statements to Congress.

Trump had insisted both during and after the election that he had no business ties to Russia, and his alleged double-dealing could have allowed Russia to use the project—which Trump had been pursuing for decades— as leverage, intelligence experts told me. The project might also contextualize Trump’s consistent and inexplicable praise for Putin along the campaign trail. “This shows motive: Trump’s desire to pursue a major deal in Russia,” Jens David Ohlin, the vice dean of Cornell Law School, told me at the time. “It finally gives Mueller some direct evidence that Trump’s associates continued to pursue business opportunities in Russia during the campaign, which would explain why Trump was, and continues to be, so deferential to Russia in general and Putin in particular. The motive was financial.”

A dossier written by the former British spy Christopher Steele in 2016, which outlined the Trump campaign’s alleged collusion with Russia during the election, raised another possibility: that Trump engaged in lewd behavior during a trip to Moscow in 2013, which was recorded and is now being held over his head. According to the dossier, the Kremlin tried to exploit “Trump's personal obsessions and sexual perversion in order to obtain suitable 'kompromat' (compromising material) on him.” Cohen told lawmakers last month that he had “no reason to believe” such a recording exists, and Trump has denied doing anything obscene while in Russia. His longtime bodyguard Keith Schiller reportedly told the House Intelligence Committee in a closed-door interview in 2017 that someone in Russia offered to send five prostitutes to Trump's Moscow hotel room in 2013, but that Schiller declined the offer on Trump’s behalf.

Mueller’s report is expected to address only criminal activity, so he might not be able to explain whether Trump has been compromised. But the president’s deference to Putin has largely continued throughout his time in office. In July 2018, for example, when the pair met for a bilateral summit in Helsinki, Trump stunned the world when he sided with Putin over the U.S. intelligence community on questions about Russia’s hacking of the 2016 election and other bad behavior. “He tells me he didn’t do it,” Trump said of Putin, referring to the election interference. “I will tell you this, I don’t know why he would do it,” Trump said. The president has also been very secretive about his private conversations with Putin, to the point where he reportedly took his interpreter’s notes from a meeting he had with Putin in Hamburg, Germany, in 2017 and tore them up. Trump also wouldn’t allow any of his aides into his private meeting with Putin in Helsinki.

Trump’s bank of choice for decades, Deutsche Bank, is another area where Democrats say Mueller should be looking to find evidence that Trump might be compromised—the German bank was involved in a massive Russian money-laundering scandal and has loaned to Trump when no one else would. The House Intelligence and Financial Services Committees have already begun talks with the bank, which said in a statement that it plans to assist the lawmakers “in their official oversight functions.”

“If the special counsel hasn’t subpoenaed Deutsche Bank, he can’t be doing much of a money-laundering investigation,” Schiff, the House Intelligence Committee chairman, said last month. “So, that’s what concerns me—that that red line has been enforced, whether by the deputy attorney general or by some other party at the Justice Department. But that leaves the country exposed.”

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