The latest pre-publication revelations from “Peril,” the forthcoming book by Washington Post reporters Bob Woodward and Robert Costa, details tensions between Donald Trump and Paul Ryan, who was convinced that the 45th president suffered from narcissistic personality disorder.

Ryan, the Speaker of the House when Trump won the presidency, was caught off guard by the results of the 2016 presidential election. Scrambling to build a rapport with Trump, he received a piece of advice from a GOP donor.

Insider summarizes:

A wealthy doctor in New York, who was also a Republican donor, contacted Ryan […] and told him, “You need to understand what narcissistic personality disorder is,” according to the book.

“What?” Ryan asked, at which point the doctor sent the Wisconsin Republican an email detailing his “thoughts on how to best deal with a person with anti-social personality disorder,” Woodward and Costa reported. The email also included links to articles about the topic in The New England Journal of Medicine, and information from the International Statistical Classification of Diseases and Related Health Problems, 10th edition.

The book said that “Ryan studied them for weeks, convinced Trump had the personality disorder.”

Ryan and Trump eventually had a confrontation over 2017’s Unite the Right Rally in Charlottesville. Ryan had condemned the event on Twitter, writing “White supremacy is repulsive. This bigotry is counter to all this country stands for. There can be no moral ambiguity.”

Insider explains what happened next:

According to “Peril,” Trump called Ryan afterward and blew up at him over the statement, shouting, “You’re not in the foxhole with me!”

“Are you finished?” Ryan reportedly yelled back. “May I have some time to speak now? You’re the president of the United States. You have a moral leadership obligation to get this right and not declare there is a moral equivalency here.”

But Trump refused to back down, saying, “These people love me. These are my people. I can’t backstab the people who support me,” according to the book.

Later, in 2018, Trump reportedly called Congress’ $1.3 trillion omnibus package a “terrible deal” and expressed his intention to veto it. Ryan eventually persuaded Defense Secretary James Mattis to pressure Trump to sign the bill.

“If you’re standing there, he’ll do it,” Paul reportedly said.