Hillary Clinton declined to wade into specifics of Trump campaign figures being indicted, saying she was “leaving it to investigators to determine if there was collusion or conspiracy.”

But she added: “We do need to get to the bottom of what happened in 2016 for the sake of our national security and our democracy.”

The same day that President Donald Trump’s former campaign chairman, Paul Manafort, was federally indicted, Clinton was in Chicago on Monday night as part of her tour to promote her book, a reflection on the 2016 presidential campaign.

It also was announced Monday that a former foreign policy adviser to Trump’s campaign, George Papadopoulos, had pleaded guilty to lying to the FBI about statements he made about contacts with Russia.

Manafort and one of his associates, Rick Gates, were charged with acting as unregistered foreign agents for Ukrainian interests. The indictments also include several other financial counts involving tens of millions of dollars routed through offshore accounts. Both men pleaded not guilty in federal court Monday afternoon.

Clinton is currently on tour across the United States, with a few stops in Canada, to promote the book, which was released last month. In “What Happened,” the former first lady, U.S. senator and Secretary of State reflects upon the 2016 election where she, despite winning the popular vote, ultimately lost her bid for the presidency.

On Monday evening, she touched on several topics she addresses in the book, from sexism in politics to media biases to the controversy surrounding her use of a private email server to conduct government business.

“When I ran [for President] in 2008, there were some very overt sexist attacks on me,” Clinton said. “I really thought that by 2016, we [had] kind of worked a lot of that out of our system. I didn’t think I’d see as much of that as I did.”

At a book signing in north suburban Winnetka on Monday morning, as news of the Manafort and Gates indictment began to take hold, Clinton said: “I have a great chapter on Russia in here.”

Despite numerous United States intelligence agencies concluding that the Russian government interfered with the election in Trump’s favor, the president and his staff have all repeatedly said there was no collusion between the campaign and Kremlin.

On Monday morning, after the indictments were announced — but before it was publicly known that Papadopoulos had pleaded guilty — Trump tweeted: “Sorry, but this is years ago, before Paul Manafort was part of the Trump campaign. But why aren’t Crooked Hillary & the Dems the focus????? ….Also, there is NO COLLUSION!”