Robert Mueller is not ending the summer with a tan. The 73-year-old special counsel leading the sprawling Department of Justice investigation into alleged ties between President Donald Trump and Russia is keeping the same grueling hours he did a decade ago as director of the F.B.I. Mueller is among the first of his team to arrive in their borrowed offices inside Washington’s Patrick Henry office building every morning and one of the last to leave each night.

More of what’s going on behind Mueller’s office door is showing up in public, though, a sign of the growing momentum of his probes into possible collusion, money laundering, election hacking, and obstruction of justice. NBC News reported that Mueller has obtained notes from the phone of Paul Manafort, Trump’s former campaign manager, that include a cryptic reference to contributions and “RNC.” The notes were apparently taken during a meeting with Russian nationals at Trump Tower. And Politico’s Josh Dawsey broke the news that Mueller has begun working with the office of New York state’s attorney general, Eric Schneiderman. (The offices of Mueller and Schneiderman declined to comment.)

The special counsel’s staff had been in touch with Schneiderman’s office for months, exchanging information and discussing whether they might coordinate their efforts, because the attorney general has spent years looking into Trump’s finances. He added to that knowledge in March by hiring Howard Master, who had been deputy chief of the criminal division under former U.S. Attorney Preet Bharara. Bharara’s office had assembled a major money-laundering case against 11 Russian companies; the scheme had been uncovered by Sergei Magnitsky, a Russian lawyer who died in a Moscow jail under mysterious circumstances. A defense lawyer who represented the Russian companies, Natalia Veselnitskaya, was part of the now-famous Trump Tower meeting, supposedly to discuss adoptions, during last year’s presidential campaign.

Also at the meeting was Manafort, a man with years of murky, multi-million-dollar international business dealings. “Manafort’s possible ties to the Kremlin are part of the investigation,” a source with knowledge of the probe says. “If he’s laundering money, you need to know who he’s laundering it for. Were they trying to buy something through Manafort? We wouldn’t necessarily need to answer that question to bring a case.”

Schneiderman’s tangled history with the Trump family adds a layer of intrigue. Back when he was merely a reality-show star and a real-estate developer, Trump donated $12,500 to help get Schneiderman elected. But in 2013 the attorney general filed a $40 million lawsuit on behalf of former Trump University students who claimed they’d been bilked. Trump filed an ethics complaint against Schneiderman, saying he’d solicited donations from Ivanka Trump while the Trump U. case was active (the complaint was dismissed). The New York Observer—owned at the time by Jared Kushner—happened to run a massive story ripping Schneiderman. And recently Schneiderman poked around inside the charities run by Trump and his son Eric.

The Russia case is, of course, strictly business. “Both Mueller and Schneiderman want to make sure they’re taking a real shot, not messing around with novel legal theory,” a source familiar with the investigation says. Schneiderman’s lieutenants have been exploring one particular piece of the puzzle since at least May: Manafort’s New York real-estate transactions. A state attorney general’s presence could also be helpful, eventually, as a legal tactic, because a president’s pardon powers do not extend to cases brought by state law enforcement. So if Manafort hoped he might become the next Joe Arpaio, the special counsel seems to have closed off that escape route.