But then again, based on what I know about him from our few in-person meetings, dozens of calls, and hundreds of texts over the past two and a half years, Kilimnik loves to partake in heated political discussions — and secretly revels in people discussing him.

The irate response from Kilimnik, a mercurial political operative who told me during our first in-person meeting in February 2017 that if he were “a real Russian spy," he "would be in Russia,” came as somewhat of a surprise. He doesn’t typically speak to reporters. And until Thursday, he and I hadn’t spoken since this February. On at least two occasions before that, he got angry with me after comments he provided for my reporting landed him in hot water with his American and Ukrainian associates.

Kilimnik was indicted by Mueller’s grand jury in June 2018 on charges of obstruction of justice and conspiracy to obstruct justice. Sometime after that, the self-proclaimed dual Russian-Ukrainian citizen, fled to Moscow, beyond the reach of US authorities. (Asked about his current whereabouts, Kilimnik told me that was “nobody’s concern.”)

If you’re one of the seemingly few people who read Mueller’s full report, you may remember Kilimnik’s name. He’s Paul Manafort’s short and shadowy former business partner and fixer in Ukraine who the FBI said had ties to Russia’s military intelligence agency. You might also recognize Kilimnik as the person who Manafort associate Rick Gates told Mueller's team had pushed the CrowdStrike conspiracy theory .

It was Konstantin Kilimnik, and he quickly launched into a profanity-laced diatribe, blasting the impeachment inquiry against President Donald Trump, arguing that a former National Security Council official who spoke about him during her testimony as part of the inquiry last month didn’t know what she was talking about, and claiming that special counsel Robert Mueller was all wrong about him.

KYIV — Late on Thursday, as I was stuck aboard a train traveling halfway across Ukraine, I sent messages over WhatsApp to a few sources to see whether they’d been following the impeachment investigation in Washington, and to hear their thoughts on the matter. Almost immediately the source I least expected to hear from wrote back.

Konstantin Kilimnik, a central figure in Mueller’s investigation, has been mostly underground for many months & not commented on the allegations against him. But in response to questions I sent on Feb. 11, he claimed the probe was “getting further and further from reality.”

The first message arrived with a soft ping, but its tone was assertive and sharp.

“Nobody seems to care about this circus other than a few thousand folks inside the Beltway and a few thousand more around the world who hate Trump,” Kilimnik said. “Ukrainians certainly do not give a damn.”

TV ratings, though, paint a different picture. On the first day of the televised impeachment hearings this week, the cumulative average US audience for the big six TV news channels — ABC, CBS, Fox, CNN, NBC, and MSNBC — was 13 million, about the same as the day Mueller testified in July, CNN reported. As for the Ukrainian reaction, Kilimnik might have a point, in part because Kyiv would much prefer to stay out of the political fight in Washington. But many Ukrainians — President Zelensky’s office in particular — are indeed watching.

My response to Kilimnik was that, yes, Ukraine feels as though it’s being dragged through the DC swamp, and sees what’s unfolding as an internal US political battle.

“Which is bad for Ukraine,” Kilimnik replied. “Brings more division and less focus on things that matter,” he wrote, mentioning the country’s war with Russia, which the new president, Volodymyr Zelensky, is trying to solve.

Hard to argue with that.

“Putin is the clear winner,” he added, referring to Russia’s President Vladimir Putin, who has sparked and fanned six years of war that has killed more than 13,000 people.

With the US neck-deep in impeachment hearings and down at least nine officials who played roles in Ukraine policy, by the New York Times’ count, Zelensky’s negotiating position ahead of new peace talks in Paris announced on Friday has been weakened.

“DC does not give a shit about Ukraine,” Kilimnik wrote to me. “It is a tool in their political fight. An object. A dildo with which Dems and GOP fuck each other.”

We then launched into the Ukrainian political weeds for several minutes. When we got back on the impeachment track, it was to discuss his name being brought up in the impeachment inquiry.

On Oct. 14, Fiona Hill, a former National Security Council official with a special focus on Russia, Ukraine, and European affairs, testified before lawmakers that she grew alarmed about the back-channel Ukraine campaign run by Rudy Giuliani, a lawyer working for Trump, and two of his associates who have since been indicted on unrelated charges of violating campaign finance laws. A transcript of her testimony was released last week.

In it, Hill is asked if she was aware that Ukraine allowed Kilimnik, a Mueller witness, to “slip across the border to Russia.”

“I was aware of that,” she replied.

Asked what more she knew, Hill explained that in a previous role at the Kennedy School of Government, she had a lot of interactions with the International Republican Institute in Moscow, where she met Kilimnik, who worked there in the early 2000s. “And all of my staff thought he was a Russian spy,” she added.

Kilimnik, who told me he met Hill “once for 10 minutes in some function back in 2005,” wasn’t pleased with her comments to impeachment investigators.

“I have zero idea why she said that. Or who her ‘staff’ she is referring to is,” Kilimnik said. “She can say all she wants. That all Russians have two penises...to fuck themselves.”

Best I could tell, he was making up an example of a weird thing Hill could say, but I’ve given up trying to figure it out.

Kilimnik also had angry words for the Mueller report, in which he was a central figure.

“Mueller made lots of mistakes about me. I never traveled to Madrid to meet Manafort. I never had a Russian diplomatic passport. I never got even a page of polling from Manafort. And I never had any ties to any intelligence,” he said, reeling off several of Mueller’s findings. “This is the truth. Anything else is lies. Or disinformation.”

About the polling Mueller said Manafort had passed on to him, Kilimnik said: “It was figures from RealClearPolitics that we discussed. Never any internal polling data - crosstabs, analysis etc.”

“I would have told this to FBI had they contacted me,” he added.

In a final attempt to find out where he was writing from, I asked Kilimnik if he was getting his US news from Russian state TV.

“They are the same propaganda as the US media. Lots of lies and wrong interpretation of insignificant details,” Kilimnik said. “Missing big picture. And creating waves of disinformation hurting their nations.”

And with that, he signed off.

“Enjoy your train ride.”