A speculation: the most common result of cracking Don DeLillo’s Underworld is that the reader finishes the brilliant 50-or-so page prologue and sort of gives up after that. Underworld, along with other tomes like Gravity’s Rainbow, Infinite Jest, and Ulysses, is a common culprit of inflicting a certain trepidation in readers. “Big-Book-Trepidation Syndrome.” BBTS is a very real condition that paralyzes otherwise competent and intellectually curious readers from diving into the great masterpieces of world literature. But Underworld, unlike these other books, offers up an aforementioned prologue that functions jointly as a standalone story.