Author Hernan Diaz discussed his new book (and his love for a particular writing element) on Seth Meyers’ late-night show Tuesday.

Diaz’s second novel, Trust, was published by Riverhead on Tuesday. The book, told in four documents, follows a wealthy New York couple in the early 20th century whose lives might not be quite what they seem. In a starred review, a critic for Kirkus called the novel “a clever and affecting high-concept novel of high finance.”

Meyers noted that the cover of the book, which depicts a skyscraper under a glass dome, looked “very familiar” to him.

“This is actually 30 Rock,” Diaz said, referring to NBC’s 30 Rockefeller Plaza in New York, where NBC’s studios are located. “The book is about money to an enormous extent, and the almost gravitational pull that money has, and its ability to distort reality and create myths around itself. And one of the ways in which it creates these myths is by monumentalizing itself through buildings, like this very building we’re in right now.”

Diaz said he wasn’t familiar with the world of high finance before doing research for his novel.

“I come from the humanities, a comp-lit background, and I’ve always been a bookish person,” he said. “And money is not, sadly to some extent, my thing.”

Diaz also revealed that he wrote his novel using a fountain pen he received as a gift 20 years ago.

“It’s a really good pen,” he said, displaying the writing implement. “It’s a posh pen.”

“Are you really snobby about your pens?” Meyers asked.

“Insufferable,” Diaz replied.

The two bantered back and forth about the pen for a while, with Meyers eventually joking, “I feel like we’re doing a weird Seinfeld episode.”

Michael Schaub, a journalist and regular contributor to NPR, lives near Austin, Texas.