All Cardenal's poetry "debunks," "corroborates," and "mediates" reality. His esthetic principles are clearly ethical, and most of his poems are more than just "vaguely" religious. (p. ix)

[All] eight texts of Zero Hour and Other Documentary Poems set out to "document" reality (and so redeem it) in a … dialectically visual way: picturing things, peoples, and events in the light of a clear-cut sociopolitical commitment; selecting, shaping, and imposing interpretative patterns on the world, with liberal use of such filmic "editing" techniques as crosscutting, accelerated montage, or flash frames; and pursuing "the redemption of physical reality" by bringing us "back into communication" with its harshness and its beauty. Poets and cameras can both affect what they record, but whereas a documentary camera's presence conditions the "on-going situation," Cardenal's recording of the present or the past is aimed at helping to shape the future—involving the reader in the poetic process in order to provoke him into full political commitment, thus fostering the translation of the poet's more prophetic visions into sociopolitcal fact. (pp. ix-x)

None of the longer poems is simple, though they all aim at surface clarity, being meant for a wide public. They are strictly "factual," but facts can be double-edged, and their juxtapositions can also set up further meanings. Cardenal's reader cannot just sit back and "listen" to the words and rhythm: he has to visualize sequences of disparate images (each one a snatched glimpse of reality), noting their pairings and progressions, matching them both with each other and with what is left unsaid—and thereby sharing in the extraction of their fuller "meaning." These poems demand more than just an alert response, because the poet wishes to prod us beyond thought and into action: his texts are never just concerned to document and understand reality, but also to help change it—which is why they have been called "The Poetry of Useful Prophecy." But the data have to be recorded before reality can be reshaped, and the reshaping lies beyond the poems themselves: the changes for which the poet yearns lie in the future. (p. x)

[The environment in "Trip to New York" is familiar] and this account of a rushed six-day trip is the closest thing in any of the longer poems to the direct reporting of immediate experience, as in a personal diary. It ought to be read, however, as a deliberately "public" diary, and also strictly as poetry: its appearance of uncommitted objectivity is a studied one, achieving its effects (as almost always in his better poems) obliquely, by poetic means—although its "images" are real, not metaphorical. They may seem as clear and as immediately revealed as snapshots taken with a Polaroid camera—photos which materialize "before one's very eyes," often still in the presence of the objects photographed (in "real life") against which one is able to control the degree of "likeness" which the camera has captured. But readers cannot match these shots against what they depict, and they have all been carefully selected and assembled…. The process is less intellectual than intuitive: when pressed to say how he selects which details of "reality" to represent, Cardenal can never rationalize his procedure, saying no more than that he "knows" which details will turn out to be "poetic" in a given context. The shots he uses are, naturally, "angled" (so are a camera's): taken from the poet's individual viewpoint, which always has inherent ethical and moral preoccupations. They have been chosen and grouped (however intuitively) with a sure sense for thematic links and quiet ironies—some of which the poet makes explicit, but not all. Thus it would be rather naïve to take "Trip to New York" as no more than a simple diary, or a piece of instant reportage couched in free verse.

Readers would do well to examine Cardenal's methods in the familiar context of that known environment before they move into the half-alien Latin American world of the remaining poems, the first of which—"Zero Hour" ("Hora 0" or "La hora cero")—is certainly the best-known of all his longer poems. As it is also the one which displays many of his favorite techniques in their most graspable form, it merits examination at somewhat greater length by way of introduction to the much later series of post-Cuban documentary poems. "Zero Hour" is in four parts: a brief opening section, in the nature of an introit, establishing the mood of Central American life under dictatorships, followed by three separate episodes. The first one concerns the economic factors underlying the politics of "banana republics"; the second is about Sandino, culminating in his treacherous execution (along with his brother Sócrates and two of his own commanders) on Tacho's orders, within three weeks of peace having been signed; while the third concerns the Conspiración de Abril, an anti-Somozan plot which misfired (in April 1954), in which Cardenal himself took part. (pp. xvi-xvii)

The whole introit depends on swiftly effective contrasts, whose "meaning" is not spoilt by being spelled out: the Guatemalan dictator with "a head cold," while his people are dispersed with phosphorous bombs; a single window of the Honduran dictator's office smashed, provoking an inappropriately violent response from armed police. Such introductory "shots" build up the setting and its atmosphere in the same terms and ways as does the opening sequence of almost any film. Other techniques which will recur appear in the three episodes. Thus the collage of documentary sources in the "economic" sequence, with its oppressive and depersonalizing lists of company names and alienating juxtapositions of contrastive factual details, will become a characteristically Cardenalian technique (one learned from Pound, and which has influenced many younger Spanish American poets through its use by Cardenal). Equally characteristic are the shafts of irony, often dependent on the reversal of an expected phrase—like "Carías is the dictator / who didn't build the greatest number of miles of railroad" (in Honduras).

The Sandino episode brings in many favorite themes: heroic self-abnegation, the purity of motives, and the egalitarian virtues of a guerrilla force "more like a community than like an army / and more united by love than by military discipline"—features he will all use much later as heroic precedents, when depicting the Sandinista guerrilleros of the following generation. At one stage, he punctuates the action with repeated snatches of "Adelita" (perhaps the favorite song of the 1910 Mexican Revolution), intensifying the vision of Sandino's forces as a "happy army" since "A love song was its battle hymn." This is a typically filmic use of song. Filmic, too, is the accelerated montage of the death sequence, with its visual and aural crosscutting between parallel actions: the exchanges between Somoza and the American minister (and later between the American minister and Moncada) punctuated by the digging of a grave, a glimpse of prisoners, and the halting of Sandino's car, whose unnamed passengers are hustled off to face the firing squad.

Similar devices are used in the third episode. Cardenal's own entry on the scene intensifies the mood ("I was with them in the April rebellion / and I learned how to handle a Rising machine gun"). Its effect is—characteristically—heightened by the lack of further elaboration, as the "I-was-there" device gives way to the stark understatement of the hunting down and slaughter of Adolfo Báez Bone, whose identification with the land in which his body lies ensures his resurrection in the collective body of his people (a theme which becomes a leitmotif in later poems). The lyrical use of landscape and the seasons to echo or contrast with man's affairs—a striking feature of both the second and the third episodes—is a device which will achieve even greater prominence in "Nicaraguan Canto," the "Oracle," and both "Epistles."

An understanding of how "Zero Hour" establishes its points helps greatly with later poems, where the chronological sequence of events is deliberately dislocated by abrupt (but often unspecified) temporal intercutting, while the poetic texture is complicated by far greater use of understated or oblique "symbolic images"—or brief references whose wider connotations only emerge with hindsight, like the thrush which "sings / in freedom, in the North" (in the first few lines of "Nicaraguan Canto"): an unstated echo of Sandino, later to be revealed as the first hint of the presence of contemporary Sandinista freedom fighters in the same Northern hills. "Nicaraguan Canto" (whose Spanish title—Canto Nacional—is as much a Nerudian as a Poundian echo) culminates in one of Cardenal's most startling tours de force: its last nine lines consist entirely of birdsong—not a device which any translator could hope to reproduce with much success.

After the "Canto," "Mosquito Kingdom" ("Reino mosco") provides easier reading, starting with the factual parody of Western pomp at the drunken coronation of a black British-sponsored puppet king as nominal ruler of the scattered nineteenth-century British settlements along the Mosquito Coast (all the way from Belize to Costa Rica), peopled by English-speaking former slaves from the West Indies, the Miskito Indians themselves, and the mixed race born of their intermarriage. The poem jumps forward in time to the pompous ostentation of Cornelius Vanderbilt's huge private yacht North Star and Vanderbilt's involvement in the attempted exploitation of that Caribbean coast, and then cuts to a series of sordid and ill-fated dealings among its actual or would-be exploiters. Although the obscurity of this facet of nineteenth-century Nicaraguan local history may puzzle foreign readers, there is no missing the point of Cardenal's satirical devices.

"Oracle over Managua" ("Oráculo sobre Managua") is a more somber and a far more complex poem. The earthquake which destroyed the city in 1972 is merely the latest stage of a long geological process, and the poem harks back to the long-past eruption which recorded the feet of fleeing prehistoric men and beasts in a layer of volcanic mud which later turned to stone, out at Acahualinca: the site of one of the worst of the shanty-towns which fringe Managua, to which the tourists and the seminarians used to go (their eyes averted from the slums) to view the Footprints. One of these seminarians, the poet Leonel Rugama, became a Sandinista, and in the sections of the poem which are addressed to him Cardenal expresses their shared view of "Revolution" as the natural next stage of "Evolution"—a process started in the stars, millions of years ago, and which will require social metamorphoses as startling as those from caterpillar into chrysalis or chrysalis to butterfly. Rugama was cornered in a house in Managua by the National Guard on January 15, 1970, along with two other young urban guerrillas, and the siege of the house where they holed up was watched by thousands of Managuans—as helicopters, planes, and even tanks were brought in to eliminate them. This small but epic incident in the Sandinista saga is made to interact, at numerous levels and in various complex ways, with the far greater catastrophe of the earthquake, in a highly intricate poetic structure.

After "Oracle over Managua," the "Trip to New York" ("Viaje a Nueva York") seems easy, and neither "Epistle" poses such problems of interpretation as the earlier poems because Cardenal's attitudes are stated more explicitly, for patently didactic purposes, while "Lights" ("Luces") is equally accessible. The visual and associative material used to frame the ideas in these four poems is, however, handled with Cardenal's accustomed skill: shifts of focus or of angle; cuts from close up or detail shots right through to extreme long; jump-cuts for the sake of concision and abruptness; the poetic equivalent of pans and zooms; deft insert shots (to give additional data); the use of flashbacks (and flash-forwards), or of bridging shots (like those of railway wheels or newspapers in films); foreshortening and forelengthening, applied both to space and to time (where films would use the time lapse camera or slow motion); studied relational editing; match-cuts which link two disparate scenes by the repetition of an action or a shape (or a sound)—but most of all the dialectical process of "collisional" montage, which generates fresh meaning out of the meanings of adjacent shots. Cardenal's highly visual poetry displays the verbal equivalent of each of those effects, and many of his most vivid sequences could almost serve as detailed shooting scripts.

All these devices, together with Poundian textual collage and the full range of more traditional poetic or rhetorical effects, are used in the course of Cardenal's documentary "redemption of reality," which successively "corroborates," "debunks," or "mediates" things, people, and events in a validation process designed to govern what we are to consider "true" and "real" and "meritorious" (or "false"—"illusory"—"contemptible") when viewed from the standpoint of his brave new revolutionary world. (pp. xxviii-xxi)