George Papadopoulos and Donald Trump Jr. had a lot in common. Both were young men brashly confident beyond their qualifications; both were feverishly trying to prove themselves to superiors inside the Trump presidential campaign. And both eagerly pursued the same angle that could instantly deliver the respect they craved: Russian-supplied “dirt” that would damage Hillary Clinton.

So one question that intrigues investigators is whether Papadopoulos and Don Jr. ever combined their efforts. Papadopoulos, as The New York Times reported, was not shy about discussing his Russian connections, most notoriously during a barroom conversation with Australia’s top diplomat in London, a chat that eventually triggered the F.B.I.’s investigation. “Bob Mueller and his team will be very carefully following up to see exactly what Papadopoulos’s favorite watering holes were and who else he might have talked to,” said Joyce Vance, a former U.S. attorney for Alabama. “But they won’t simply be looking at his social activities. This is someone inside of the campaign who was promoting Russian contacts. Who else in the campaign knew that it was going on? They’ll definitely want to know what sorts of conversations he had with Jeff Sessions, who was Papadopoulos’s boss on the national security committee. But this campaign didn’t always follow the lines of the chain of command.”

That’s an understatement. Papadopoulos’s approach seems to have been to try to get the attention of as many Trump campaign officials as possible, in an attempt to promote what he called an “open invitation” from Vladimir Putin to meet with Trump. It’s clear, from his plea agreement with Mueller, that the outreach included e-mails to Sam Clovis, Trump’s national campaign co-chairman; Paul Manafort, for three months the campaign’s chief; Stephen Miller, senior policy adviser in the campaign and now in the White House; and Corey Lewandowski, who managed the campaign early on and remains a Trump confidant.

Trump Jr., meanwhile, was operating on a parallel track. In early June 2016, he received an e-mail from publicist Rob Goldstone offering to broker the delivery of “official documents and information that would incriminate Hillary and her dealings with Russia.” “If it’s what you say I love it,” Don Jr. replied, and less than a week later he was meeting with a woman billed as a “Russian government attorney” in a Trump Tower conference room one floor below his father’s office, with Jared Kushner and Manafort also representing the campaign.

Perhaps Goldstone’s e-mail alone was enough to stoke Don Jr.’s excitement about the gathering. But weeks earlier, Papadopoulos had been told that the Russians possessed “dirt” on Clinton in the form of “thousands of e-mails.” Did that tempting offer make its way from Papadopoulos to Don Jr.? And did Don Jr. expect the Russians to deliver the material at the Trump Tower meeting?