Here’s what Mueller will want to ask Manafort now that he’s agreed to talk

Paul Manafort, President Trump’s former campaign chairman, has promised to tell investigators everything he knows about what really went down during the 2016 campaign.

He may know a lot.

Manafort spent six months atop the Trump campaign at a time when Russia was allegedly trying to tip the election in Trump’s favor. And Manafort had arrived in Trumpland with a vast network of contacts with ties to the Kremlin. Right before signing up with Trump in spring 2016, Manafort had just wrapped up a decade working closely with powerful Ukrainian and Russian tycoons broadly aligned with Russian President Vladimir Putin.

Read: Paul Manafort has agreed to cooperate with special counsel Robert Mueller

On Friday, Manafort pleaded guilty to reduced charges brought by special counsel Robert Mueller’s team, and signed a sweeping deal pledging effectively limitless cooperation.

“This is the most dramatic moment in the investigation thus far,” Seth Waxman, a former federal prosecutor, told VICE News. “Mueller’s team put a lot of resources into going after Paul Manafort. He’s a key individual in the investigation.”

Mueller, who is probing whether the Trump campaign cooperated with Russian efforts to impact the 2016 election, will have a lot ask Manafort about.

Here are some of the areas Manafort can be most helpful in clearing up.

In June 2016, at the height of the campaign, Manafort huddled with a small group of top Trump campaign officials in Trump Tower across the table from a lawyer from Moscow named Natalia Veselnitskaya. She’d scored the meeting under the promise of bringing dirt on Trump’s opponent, Hillary Clinton.

When the meeting came to light months later, Trump’s circle claimed the whole thing had been a big waste of time, and that nothing of substance had been discussed.

But the Trump team’s version of events has been a moving target. Don Jr. initially released a statement saying the group discussed the adoption of Russian children. Later, Trump himself admitted the meeting was aimed at obtaining dirt about his opponent.

Trump’s lawyer, Rudy Giuliani, has insisted Trump didn’t know about the meeting at the time, even though it was attended by Manafort, Don Jr., and Trump’s son-in-law, Jared Kushner.

Manafort is now in a position to shed light on that mysterious gathering, and potentially explain just what exactly was discussed in Trump Tower on that summer day. He may even be able to provide details regarding how much Trump himself really knew about the whole thing.

During his years working for former Ukrainian President Viktor Yanukovych, Manafort’s right-hand man was a translator named Konstantin Kilimnik.

And Kilimnik, according to Mueller’s team, had ties to Russian intelligence that remained active during the 2016 U.S. presidential campaign.

Kilimnik has strenuously denied that claim, but he has also gone quiet in recent months as the investigation has heated up. This summer, he was indicted in the Mueller probe himself, alongside Manafort, over allegations of witness tampering in Manafort’s case.

Read: Exclusive: First photos emerge of shadowy Manafort aide tied to Russian intelligence

Kilimnik kept in touch with Manafort during the campaign, and traveled to the U.S. to meet with Manafort at least twice. He was also in communication with Manafort’s deputy on the Trump campaign, Rick Gates, even after Manafort was forced out in August 2016, according to documents released in the Mueller probe.

Manafort will now be obliged to answer questions about all of his communications with Kilimnik during the campaign, and about his knowledge of Kilimnik’s background — including any links to Russian intelligence.

During the campaign, Manafort told Kilimnik to offer up “private briefings” to a Russian oligarch seen as very close to the Kremlin named Oleg Deripaska, according to email records published by The Washington Post and The Atlantic.

Deripaska has repeatedly denied receiving that offer, let alone the briefings.

But within hours of a subsequent meeting between Manafort and Kilimnik in Manhattan in early August 2016, Deripaska’s private jet flew in from Moscow and spent just a few hours on the tarmac in nearby Newark, New Jersey. Then it took off and returned to Moscow.

Deripaska's spokesperson told VICE News that the jet was carrying “Mr. Deripaska’s family only,” and repeated that the Russian businessman had no interactions with Manafort during this time period.

“Mr. Deripaska had no communications, meetings, briefings, or other interaction with Mr. Manafort during, after, or in the run-up to the 2016 presidential election,” the spokesperson told VICE News at the time.

Read: Paul Manafort, a Russian jet and a secret meeting during the 2016 campaign

A month after that jet staged the brief landing in Newark, FBI agents showed up at one of Deripaska’s residences in New York and tried to get him to become an informant, The New York Times reported earlier this month. Investigators pressed Deripaska about whether Manafort had been a link to the Kremlin while working for the Trump campaign, according to the Times.

In April, Deripaska was slapped with sanctions by the U.S. for what the Treasury Department described as broad punishment for Russia’s “worldwide malign activity,” including, among other actions, “attempting to subvert Western democracies.”

Manafort had a previous business relationship with Deripaska that had gone sour, and he was being pursued by Deripaska’s lawyers for millions.

Manafort will now have to tell Mueller’s investigators all about his relationship with the Russian oligarch, and whether their communications during the campaign were more substantial than has been previously acknowledged.

Cover image: Paul Manafort, campaign chairman for Republican Presidential Candidate Donald Trump and his assistant Rick Gates (left) stand on the floor of the Republican National Convention in Cleveland, U.S. July 17, 2016. REUTERS/Brian Snyder/File Photo