[1] The narrative takes place between the 1893 Chicago World's Fair and the time immediately following World War I and features more than a hundred characters spread across the United States, Europe, Mexico, Central Asia, Africa and "one or two places not strictly speaking on the map at all," according to the book jacket blurb written by Pynchon.

Besides appearing within the book itself, the novel's title apparently refers to a verse in the Bible (2 Peter 3:7) reading "the heavens and the earth ... [are] reserved unto fire against the day of judgment and perdition of ungodly men.

in which Sutpen, a Faustus character of the sort that Pynchon deploys everywhere, seeks "a wife who not only would consolidate the hiding but could would and did breed him two children to fend and shield both in themselves and in their progeny the brittle bones and tired flesh of an old man against the day when the Creditor would run him to earth for the last time and he couldn't get away."

"With a worldwide disaster looming just a few years ahead, it is a time of unrestrained corporate greed, false religiosity, moronic fecklessness, and evil intent in high places.

Pynchon promises "cameo appearances by Nikola Tesla, Bela Lugosi and Groucho Marx", as well as "stupid songs" and "strange sexual practices".

The synopsis concludes: The published jacket-flap of the book featured an edited-down version of this text, omitting the last three sentences, references to specific authorship (as well as misspelling Nikola Tesla's first name as "Nikolai"; Pynchon had previously spelled it correctly).

This advance was fired by some mixed-up combination of abstract mathematical speculation, capitalist greed, global geopolitical power struggle, and sheer mysticism.

[12] "Pynchon makes much of a variety of calcite called Iceland spar, valued for its optical quality of double refraction; in Pynchonland, a magician can use it to split one person into two, who then wander off to lead their own lives", Seligman writes.

[15] Light appears as a religious symbol or element and as a scientific phenomenon, as Peter Keouge, in his Boston Phoenix review[13] points out: In his Bloomberg News review, Craig Seligman portrays the book as "overstuffed with wonders" often related to light, including a luminous Mexican beetle and the Tunguska Event of 1908 that leaves the native reindeer soaring and "stimulated by the accompanying radiation into an epidermal luminescence at the red end of the spectrum, particularly around the nasal area" (reminiscent of the luminescence of a certain fictional reindeer).

[2] Scott McLemee sees connections between light, space-time and politics:[16] It remains unclear whether Pynchon himself regards such escape or transcendence as really possible.

For example, Laura Miller in Salon.com: Time doesn't exist, but it crushes us anyway; everyone could see World War I coming, but no one could stop it — those are two weighty paradoxes that hover over the action in "Against the Day" without truly engaging with it.

[18] New York Times reviewer Michiko Kakutani writes of the characterizations: "[B]ecause these people are so flimsily delineated, their efforts to connect feel merely sentimental and contrived.

[20]As a complement to Miller's criticism about tragedy, Adam Kirsch sees comedy as undercut as well, although parody remains: The gaudy names Mr. Pynchon gives his characters are like pink slips, announcing their dismissal from the realm of human sympathy and concern.

This contraction of the novel's scope makes impossible any genuine comedy, which depends on the observation of real human beings and their insurmountable, forgivable weaknesses.