The answer to where Robert Mueller is going with his prosecution of Roger Stone could have a lot to do with conspiracy theorist Jerome Corsi.

Stone, who was arrested last week at his home in Florida, has long had one big question swirling around him: Was he was somehow involved in the “hack and leak”? That is, the hacking of leading Democrats’ emails by Russian intelligence officers, the provision of those emails to WikiLeaks, and the eventual public release of those stolen emails.

Stone has denied any involvement. But Corsi — known as “Person 1” in Stone’s indictment — was questioned by Mueller’s prosecutors on this topic extensively, over multiple sessions late last year. In recent months, he’s gone public, giving many media interviews. He even released a book called Silent No More: How I Became a Political Prisoner of Mueller’s “Witch Hunt,” giving what he says is an account of what happened.

The book should be read with heaping piles of salt. Before Mueller’s investigation, Corsi was best known as the pundit who helped popularize conspiracy theories that claimed Barack Obama wasn’t born in the United States and/or was a secret Muslim — neither of which was true. The new book, too, makes many claims about Corsi’s state of mind, intentions, and memories that don’t seem particularly believable.

But, interestingly, Corsi goes into a whole lot of detail about what Mueller’s prosecutors asked him, and what evidence they told Corsi they had. Here, Corsi makes some surprising disclosures — and admissions — that really could shed light on Mueller’s investigation.

These parts of Corsi’s book, which he says are based on notes his lawyer took during the questioning sessions, seem largely credible. Indeed, Corsi has already backed up some of them by releasing a draft plea deal document Mueller put together for him. That document really did provide us a glimpse into the investigation’s future — two months later, Mueller cited much of the same evidence the draft included for his actual indictment of Roger Stone.

Indeed, presenting accurate information about what Mueller has might be exactly what Corsi wants. By publishing this book, Corsi is publicly airing every detail he knows about what Mueller knows, and what areas of inquiry Mueller’s pursuing. Doing so could undercut the investigation. And if Corsi can make a lot of money from book sales at the same time ... well, that’s a win-win for him. Unless, of course, he does end up getting charged.

So here’s what the book claims.

Back up — who is Jerome Corsi, and why does Mueller care about him?

After a career in the finance industry, Corsi first entered the national stage in 2004, as a co-author of the Swift Boat Veterans for Truth book attacking John Kerry’s military service. After that, he got a columnist gig at the fringe conservative website WorldNetDaily, and he’s been stoking conspiracy theories ever since, including that Barack Obama wasn’t born in the United States. (My colleague Jane Coaston and I did a deeper dive into his history last year.)

It was in February 2016, Corsi claims in his book, that he first met Roger Stone. At first interviewing him for an article, Corsi says they developed a bond and began working “secretly” together to help Trump win.

But Corsi didn’t get all that much attention during the campaign. Stone, however, did. The longtime Trump adviser publicly said many times that he had information about WikiLeaks’ plans — a document release that would be devastating for Hillary Clinton.

So after WikiLeaks eventually did begin posting Clinton campaign chair John Podesta’s hacked emails in October 2016, questions arose about what Stone knew or whether he was involved in some way (which he denied). Particularly suspicious was a tweet Stone had sent the previous August, predicting it would “soon [be] the Podesta’s time in the barrel.”

Mueller has been vigorously investigating the question of what happened with the emails, and has already accused 12 Russian intelligence officers of involvement in the hack. The special counsel’s team also began questioning more than a dozen associates of Stone. So they questioned Jerome Corsi. The main purpose, it seems, was to find out whether Stone indeed was informed about or involved in the release of Podesta’s stolen emails.

What Corsi says he admitted about Stone and WikiLeaks

Corsi first went in to talk with Mueller’s prosecutors on September 6, 2018 — and he had little to offer. Asked whether he helped Stone get in touch with WikiLeaks, he denied doing any such thing. Instead, Corsi claimed, he warned Stone that such activity could expose him to surveillance and investigation.

Mueller’s team then broke off the interview, per Corsi, who writes that one prosecutor said they have “demonstrable proof that what you said was false.” They suggested he review his old emails and come back for another session. (This is all backed up by the draft plea deal document Corsi leaked. In fact, Stone had sent Corsi a July 2016 email telling him to “Get to Assange,” and Corsi forwarded it to an associate based in the United Kingdom, Ted Malloch.)

But before the next session, Corsi writes, Mueller prosecutor Aaron Zelinsky agreed to give Corsi’s lawyer David Gray more details about what to expect in the next session of questioning. According to Corsi, Zelinsky told Gray:

That they had evidence Corsi was telling multiple people (including Stone) that Assange had John Podesta’s emails, all the way back in August 2016, more than two months before that news became public.

That Corsi was even saying that Assange planned to release those emails in October, in a “drip-drip-drip” fashion (which proved spot-on).

That they had evidence that Stone called Corsi shortly before the Access Hollywood tape (the 2005 recording in which Trump bragged about grabbing women “by the pussy”) was released, and urged him to get word to Assange to start dumping the Podesta emails. (This is a particularly interesting claim because the first batch of Podesta emails was indeed released half an hour after the Access Hollywood tape was. There has long been speculation that the timing was connected, but there hasn’t been evidence to support that.)

In Corsi’s second round of questioning with Mueller’s team on September 17, 2018, he says he admitted that all this was true. He also admitted that he helped Stone concoct a “cover story” to explain away that suspicious Podesta tweet.

This would seem to suggest Trump associates had good advance information about the stolen (Russian-hacked) Podesta documents. It also suggests some sort of effort at coordinating the release of those emails to benefit Trump’s campaign.

Except ... Corsi goes on to claim that all this is a lot less damning than it looks.

Corsi still insists there was no collusion with WikiLeaks

First, Corsi says he continued to insist to Mueller’s team that despite what his emails might suggest, he actually never did get any inside information from WikiLeaks or any intermediary. Instead, he claimed he’d simply “figured out” that what Assange had was Podesta’s emails. (His book includes a lengthy chapter purporting to explain how he did so, jumping from computer systems to Assange’s public comments to Seth Rich’s murder, but I found his explanation nonsensical.)

Second, on the Access Hollywood tape day, Corsi says he never did successfully get in touch with Assange. So in the end, there was no actual collusion or contact with WikiLeaks that Corsi knew about, or so he claims. (“I continue to suspect that Stone had other sources that provided him access to Assange and WikiLeaks,” he writes.)

Mueller’s team did not believe this story, according to Corsi. He writes that they kept pressing him to explain who his real WikiLeaks contact was but had no luck. Their talks fell apart, and they eventually tried to get Corsi to admit making false statements as part of a proposed plea deal — a deal Corsi rejected.

Corsi’s book discloses much of the evidence Mueller shared with him

Even though Corsi continues to (questionably) insist that he never had inside WikiLeaks info, what he does admit is a huge problem for Roger Stone.

Stone has insisted for more than two years, including in testimony to the House Intelligence Committee, that he had no idea WikiLeaks had Podesta’s emails and that his ominous “barrel” tweet was just a coincidence. More recently, he said he had no idea the Access Hollywood tape was coming in advance. In response to Corsi’s claims, Stone has furiously lashed out at him, calling him a liar, a drunk, and a “Judas.”

Indeed, if all Mueller had was Corsi’s word against Stone’s, he likely wouldn’t have a strong case. But according to Corsi’s book, again, it was Mueller prosecutor Zelinsky who said he could already prove all this, and had evidence backing it up:

Zelinsky told David Gray that Stone had told me in advance about the Billy Bush video and asked me to get word to Assange to hold the release of the first batch of the Podesta emails until after the Washington Post had published the damaging Billy Bush “hot mic” recording. That is exactly what happened.

Specifically, Corsi makes clear, Mueller has lots of emails and call records — records that Corsi helpfully describes in detail, paired with what he allegedly told Mueller’s team about them.

I don’t have enough space to go through all of them here, but one set I found particularly interesting was Corsi’s phone records from October 7, 2016 — hours before the Access Hollywood tape and Podesta’s emails were both released. (All times Eastern.)

11:27 am: Corsi calls Roger Stone and they speak for one minute. (Corsi says this happened at 11:27 pm but given the timeline, I think this is a typo.) 1:08 pm: Corsi joins a conference call for WorldNetDaily (the conservative website he works for), which lasts 28 minutes. 1:42 pm: Stone calls Corsi; they speak for 18 minutes. 2:00 pm: Corsi has a call with Total Banking Solutions, a deposit brokering company he says he’s consulting for. 2:18 pm: Corsi calls Stone back. They speak for 21 minutes.

The Access Hollywood tape came out around 4 pm, and WikiLeaks started releasing the Podesta emails around 4:30 pm.

Corsi’s purported recollection of what happened here, which he says he told Mueller’s team, is that most of these calls were about Stone’s news that the damaging tape on Trump would soon be released, and his desire to get WikiLeaks to start dumping the Podesta emails to counteract it.

He writes that he explained all this on the conference call with the staff of WorldNetDaily — meaning there would be witnesses to back up his version of events, if it’s true. (Perhaps some of those witnesses talked to Mueller already.)

Corsi is cagier, however, about what he said on his call with Total Banking Solutions. This is a financial company Corsi says he was consulting for — along with Ted Malloch, the person to whom Corsi forwarded Stone’s older “Get to Assange” email. Corsi does not clearly explain who was on this call or what happened.

In the end, Corsi writes, “I believe I made clear to Roger Stone that I had no way to contact Assange directly and I do not recall having any source who I knew to be in contact with Assange.” However, he continues, Mueller’s team confronted him with a later email that seems to contradict this.

Zelinsky revealed that after October 7, 2016, the prosecutors had evidence of an email exchange between Stone and me in which Stone expressed pleasure that Assange had released the Podesta emails as instructed, and in which I replied that Stone and I “should be given credit.”

So while we still lack a definitive narrative of what happened that day, it certainly seems to have been a busy one.

What does it all mean?

Obviously, we shouldn’t take Corsi’s book — and particularly his repeated claims of innocence and memory failure — at face value.

The way Corsi narrates the above events, he was a well-intentioned guy who genuinely intended to cooperate with Mueller, honest. But over many hours of questioning, he was sadly plagued by his poor memory of events from two years ago, caught in a dastardly “perjury trap,” and eventually unsuccessfully pressured to admit to things he didn’t do.

But a cynic might read the events recounted in this book and conclude that Corsi’s behavior matches quite well with a calculated strategy: to admit everything he thought Mueller’s team could already prove, and claim memory failure on everything else.

For instance, the draft plea document alleges that Corsi had deleted his emails from before the Podesta release. Perhaps in his first session with Mueller’s team he thought that deletion had worked — and when he learned it didn’t, and that they had his emails, he tried to shift his story somewhat, while still trying to hide what actually happened.

While it’s tempting to dismiss Corsi’s book as entirely made-up nonsense, Mueller has already made clear that it’s not so simple. The special counsel cited much of the email evidence Corsi describes in his book in his indictment of Stone. So Corsi’s narrative seems untrustworthy, but he does not appear to be fabricating these emails and phone records. And his accounts of what Mueller’s team is asking about match reports from other sources.

What the book seems to suggest, then, is that Mueller was intently interested in making some sort of case against Stone directly involving WikiLeaks and the Podesta emails — and that he assembled a good deal of evidence toward that end.

It’s possible he decided that in the end, investigators didn’t have enough evidence to indict Stone on this. But the special counsel could also still be pursuing that part of the probe — meaning more charges against Stone (and perhaps also Corsi) could be coming.

For more on the Mueller probe, follow Andrew Prokop on Twitter and check out Vox’s guide to the Trump-Russia investigation.