Days after becoming a foreign policy advisor for the Trump campaign in 2016, George Papadopoulos started meeting with a woman he believed to be Vladimir “Putin’s niece,” according to a newly unsealed indictment by special counsel Robert Mueller.

The woman, along with a Kremlin-connected, London-based professor, wanted to help Papadopoulos arrange meetings between representatives of then-candidate Donald Trump and Russian President Vladimir Putin. Maybe, the woman said, she could even get the two men to meet face-to- face.

“I have already alerted my personal links to our conversation,” she later emailed. “As mentioned we are all very excited by the possibility of a good relationship with Mr. Trump. The Russian Federation would love to welcome him once his candidature would be officially announced.”

But the woman was not, in fact, Putin’s relative. Papadopoulos had, in a sense, been catfished—and then lied about catfishing to federal investigators.

Papadopoulos, who was arrested in late July, pled guilty to making false statements to the FBI. That plea was unsealed on Monday—as were court paper showing that Papadopoulos, the professor, and the so-called “niece” had been part of an effort to establish a back channel between Trump and the Kremlin, and to obtain thousands of Clinton emails before anyone knew those messages had been hacked.

Papadopoulos was living in London when he was named a foreign policy advisor to Team Trump in March 2016. Approximately eight days after accepting the job, Papadopoulos met another Londoner: a Russian professor who “claimed to have substantial connections with Russian government officials,” the indictment reads.

One of those connections was of particular interest to Papadopoulos. On March 24, the professor invited Papadopoulos to a meeting with a Russian woman, whom he introduced as a relative of Russian president Vladimir Putin. After the meeting, Papadopoulos wrote an email to the Trump campaign, stating that he had just met with the professor, whom he described as a “good friend,” and the alleged “niece.”

Papadopoulos said “Putin’s niece” and the professor had offered “to arrange a meeting between us and the Russian leadership to discuss U.S.-Russia ties under President Trump.”

The woman also allegedly promised to introduce Papadopoulos to the Russian Ambassador in London, but never made good on the offer.

But Trump campaign staffers praised Papadopoulous’ new connections. “Great work,” an unnamed campaign supervisor replied to the email. The supervisor shied away from making any early commitments to a meeting, but promised to “work it through the campaign.”

When Papadopoulos met with Trump and campaign staffers in person later that month, he introduced himself as having connections that could arrange a face-to-face meeting between Trump and Putin. An Instagram post from Trump’s account shows Papadopoulos at the meeting, along with members of the foreign policy team and future Attorney General Jeff Sessions. Absent from that group was foreign policy advisor Carter Page, whose communications with Russian officials have also been the subject of investigation.

After the meeting, Papadopoulos, the professor, “Putin’s niece,” and an official in Russia’s ministry of foreign affairs were in frequent communication about a possible meeting.

“I have already alerted my personal links to our conversation and your request,” the woman posing as Putin’s relative wrote Papadopoulos in April. “As mentioned we are all very excited by the possibility of a good relationship with Mr. Trump.”

Then, on April 26, Papadopoulos met the professor for breakfast at a London hotel. The professor confided in him that he had just been to Moscow, where high-level Russian officials had talked of obtaining “dirt” on Hillary Clinton. “The Russians had emails of Clinton,” the professor told him, according to the indictment. “They have thousands of emails.”

The timing of the leak is critical. The rest of the world did not learn about the Clinton campaign’s and the Democratic National Committee’s leaked emails until months later. But the breach began on March 19, when Clinton campaign chair John Podesta clicked on a phishing link, the New York Times previously reported. In April, the Russian hacking group known as Fancy Bear breached the Democratic National Committee, a report by CrowdStrike found. Those emails did not surface online until July 22.

The day after meeting with the professor, Papadopoulos emailed what the indictment describes as an unnamed “senior policy advisor” and an unnamed “high-ranking campaign official” about “interesting messages coming in from Moscow.” Papadopoulos pressed again for the campaign to arrange an in-person meeting between Trump and Putin in Moscow.

While the recipients of those emails are unnamed in the indictment, an August report by the Washington Post revealed sent then-campaign manager Corey Lewandowski an April 27 email, stating that “Putin wants to host the Trump team when the time is right,” an invitation that intelligence officials speculated might have been a Russian effort to gauge the Trump campaign’s receptiveness to cooperation.

Over the next several months, Papadopoulos made repeated attempts to send Trump or campaign officials to a meeting in Moscow. The Trump campaign appeared receptive. After weeks of communication about an “off the record meeting” with Russian officials, a Trump campaign supervisor told Papadopoulos in August that “I would encourage you” and another foreign policy advisor to “make the trip, if it is feasible.”

The meeting never materialized. But Papadopoulos’ communications with the professor, the Russian foreign ministry official, and “Putin’s niece” attracted FBI’s attention.

In late January 2017, FBI officials interviewed Papadopoulos about his interactions with Russian officials. Papadopoulos repeated claimed the communications occurred before he joined the Trump campaign.

“This isn’t like [the professor]’s messaging me while I’m in April with Trump,” he told investigators, according to the indictment. “I wasn’t even on the Trump team, that wasn’t even on the radar … This was a year ago. This was before I even got with Trump.” He conceded that it was a “very strange coincidence” to have learned about the “dirt” on Clinton a year before joining the Trump campaign.

Papadopoulos downplayed the professor’s Kremlin ties, calling the man “a nothing” and “just a guy talk[ing] up connections or something.” Papadopoulos claimed he thought the professor was “BSing to be completely honest with you.”

Papadopoulos also minimized his interactions with the woman he had described as “Putin’s niece,” telling FBI investigators that he had no relationship with her, other than sending emails that amounted to “hi, how are you?”

None of those claims were true. Not only did Papadopoulos knowingly connect with the Kremlin-linked professor after he joined the campaign, he also met the mystery Russian woman in person, and Skyped with her multiple times, according to the indictment.

FBI officials interviewed Papadopoulos again on February. The following day, he deleted his Facebook account, where he had been communicating with the professor and a Russian official, and created a new account, scrubbed of all the old messages. Days later, Papadopoulos ditched his phone and started using a new number.

He was arrested July 27 in Dulles International Airport, according to his indictment. Since his arrest, which remained secret until now, Papadopoulos has met with investigators to answer more questions—and cooperate with Robert Mueller’s ongoing probe of ties between Trump Tower and the Kremlin.

“We look forward to telling all of the details of George’s story at the time,” Papadopoulos’ attorney said in a statement.