According to his own records, Trump Jr. was told by an intermediary, publicist Rob Goldstone, that the dirt was sourced to Moscow, which sought to share it as "part of Russia and its government's support for Mr. (Donald) Trump."
"(If) it's what you say I love it," Trump responded, then rounded up the campaign's top officials -- son-in-law Jared Kushner and then-chairman Paul Manafort -- and, as he tells it, led them unwittingly into a room with Natalia Veselnitskaya, the so-called Kremlin-connected lawyer believed to be carrying the compromising information.
Even with the new details now emerging, this is a story that, as ever, begs still more questions. Here are five.
Even after he released his emails Tuesday, the going assumption seems to be that Trump Jr.'s account of the actual meeting, the one described in his second statement, was accurate. That seems odd (and maybe dumb) in retrospect.
Here is the relevant recollection, as laid out on Sunday.
"After pleasantries were exchanged, the woman stated that she had information that individuals connected to Russia were funding the Democratic National Committee and supporting Ms. Clinton. Her statements were vague, ambiguous and made no sense. No details or supporting information was provided or even offered. It quickly became clear that she had no meaningful information."
At that, he said, the conversation shifted to other matters. Or did it? Again, multiple members of the Trump campaign, its inner circle and "satellites,"
as the President described them, have now changed their stories after being confronted by new reporting. (This includes high level officials like former National Security Adviser Michael Flynn, Attorney General Jeff Sessions, Trump son-in-law and top adviser Jared Kushner and former campaign chairman Paul Manafort. There are more.)
So what else, if anything, was said at Trump Tower on June 9, 2016?
2. Did Jared Kushner and Paul Manafort know what Trump Jr. had been told in his email?
Two people who might be able to share some more detail about the meeting are Kushner and Manafort. They were there, at Trump Jr.'s request, but have been publicly mum on the matter.
But let's rewind again to Monday's questions. As seen in the emails Trump Jr. shared on Twitter, he did not walk blindly into the meeting. Goldstone told his friend to expect "official documents and information that would incriminate Hillary and her dealings with Russia and would be very useful to your father."
"This is obviously very high level and sensitive information," he added in the email, "but is part of Russia and its government's support for Mr. Trump."
What we still don't know and, judging by their attorney's comments, are unlikely to find out any time soon, is whether Manafort and Kushner were fully briefed before sitting down. As Trump Jr. explained it in his Sunday statement, the 2.0 edition of his story, "I asked Jared and Paul to attend, but told them nothing of the substance."
The details in the email shared by Trump Jr. make this more difficult to believe. He did not simply gather his father's top lieutenants without notice from their workspaces or pick them off at the water cooler. Kushner and Manafort knew about the meeting, if the emails are accurate, at least a day or two before it was scheduled to happen, because Trump Jr. forwarded it to them.
Stringing it all together, Trump Jr.'s official line now contends that Kushner and Manafort, despite having so much lead time, ultimately took the meeting with no hint (or apparent interest) in its purpose. Which, to put it mildly, doesn't make a whole lot of sense.
3. Was this the only meeting?
There is now a paper trail that shows Trump Jr. walked into the meeting with Veselnitskaya, described in an email as a "Russian government attorney," fully aware -- or at least with the belief -- that she was there to peddle damaging information about Clinton. And that whatever materials or knowledge she was bringing were sourced to Moscow.
Trump Jr. has said the meeting was a dud. What is still unclear, however, is whether it was a one-off.
That, of course, would be an issue in its own right. But if the acquaintances who arranged the talk felt comfortable enough to email about the provenance of the information in the first place, it's worth asking what else he might have shared.
A lot of people tied up in this narrative have claimed bad memories. If more emails emerge, perhaps they'll start remembering.
4. Are there (even) more emails?
There is already a steady flow of speculation into who initially provided the Times with such detailed and, as we've seen Tuesday, accurate information about the emails. But the more pertinent, if potentially less salacious, question centers on whether those individuals are going to chat with special counsel Robert Mueller.
For all we know, right now, they already have.
Which brings us to the question of motivation. One would imagine that people in a position to put eyes on a document like this would be personally close to Trump Jr. The Times report from Monday night cited "three people with knowledge" of its contents.
What else have they seen?
5. What did the President know and when did he know it?
It's that time.
The question, which has become a kind of mantra in these settings, gets thrown around a lot. Probably too much. Tennessee Sen. Howard Baker Jr. coined it during the Watergate era -- a neat query that, if answered faithfully, drives to the center of any potential scandal involving the White House and its affiliates.
Trump was not traveling on June 9, 2016, the date now under such heavy scrutiny. A spokesman for his legal team said on Sunday that he "was not aware of, and did not attend, the meeting."
If, and when precisely Trump was clued in -- will go a long way in determining the depth and scope of his campaign's activities.