NEW YORK (CBSDFW.COM/CNN Money) – Former FBI director James Comey sat down with Stephen Colbert on “The Late Show” on Tuesday for a wide-ranging interview that touched on President Donald Trump, the Russia investigation and a little bit of red wine.

“When you were fired,” Colbert said during the taping, “you say in the book that, when it was over, you flew back on a plane to the east coast drinking Pinot Noir in a paper cup.” The host then pulled out the bottle of wine and two paper cups and made a toast with Comey.

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“To the truth,” Colbert said.

The late night show was Comey’s latest stop on his book tour for “A Higher Loyalty,” a new memoir that offers insight into his termination as FBI director. The book, which officially went on sale Tuesday, is shaping up to be one of the biggest bestsellers of the year. Comey’s publisher printed 850,000 copies to meet the expected demand.

(credit: CBS)

“Of all the people to be fired by Donald Trump, my guest tonight is definitely one of them,” Colbert said, introducing Comey to the audience. The former FBI director walked out onto the stage to a standing ovation. The two men then talked for more than 30 minutes.

Colbert kicked off the conversation by asking Comey for his loyalty, and insight into the Russia investigation that isn’t public.

“Can you tell me?” Colbert asked.

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“Uh, no,” Comey answered.

“Okay, drink some more wine,” Colbert said.

The conversation moved quickly and culminated in a lightning round of questions.

“What happens if Mueller gets fired,” Colbert asked. “Does the investigation go on?”

“I think you would need to fire everyone in the Justice Department and the FBI to stop that investigation,” Comey replied.

“Well, it’s hard to fire the FBI director, too,” Colbert said.

Colbert’s relentless mockery of the Trump administration has helped him top his rivals in the ratings by a sizable margin. The ratings reports on Monday showed that Colbert averaged 4 million viewers in the first quarter of 2018, which amounts to a 20 percent spike compared to 2017 and a staggering 1.2 million more viewers than rival Jimmy Fallon.

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(© Copyright 2018 CBS Broadcasting Inc. All Rights Reserved. Cable News Network contributed to this report.)