This is the first poem in Fleur Adcock's collection Looking Back (Oxford, 1997).
WHERE THEY LIVED
That's where they lived in the 1890s.
They don't know that we know,
or that we're standing here, in possession
of some really quite intimate information
about the causes of their deaths,
photographing each other in a brisk wind
outside their terrace house, both smiling
(not callously, we could assure them),
our hair streaming across our faces
and the green plastic Marks and Spencer's bag
in which I wrapped my camera against showers
ballooning out like a wind-sock
from my wrist, showing the direction
of something that's blowing down our century.
Who are "they"? Either they are famous people, or they are relatives of "us"; otherwise, "we" would not know the intimate details of "their deaths." The latter is more likely, as famous people might actually expect people a hundred years later to remember them; hence, they would "know that we know." So "they" are quite likely "our" ancestors.
The present tense in "they don't know that we know" is quite striking; a more straightforward version of the sentence would be this: "They didn't know that we would know." It's possible to object to that formulation; after all, people at least hope that their descendants will remember them, will be on familiar terms with them, will know "where they lived." But of course that hope is different than knowledge; to rephrase it again: "They couldn't know for sure that we would know."
The double present tense that Adcock actually uses, though, collapses a century into a moment of simultaneity, as if we and our ancestors live in the same moment, separated only by knowledge and ignorance: we know the rest of their lives, and all that has happened since, and they don't. This knowledge is vague in the poem; at two key moments (in lines 4 and 14), specifics are absent, replaced by "some" and "something." The "intimate information" is not specified, nor is the implicitly more public information "that's blowing down our century." In the frame of the poem (the first five lines and the last line-and-a-half), information is referred to but not spelled out.
In contrast, the scene involving "us" that begins in line 6 is much more specific. Even as "we" take photographs of each other, the poem itself becomes much more like a photograph, with the visual details of the terrace house, of hair and faces, and of the elaborately described plastic bag. The house and the wind in "our" faces are images "they" might have experienced when they lived here; these images confirm the double present tense that connects them and us. But the plastic bag separates ancestors and descendants, as something the former would not have known. The camera is more ambiguous, as cameras were invented much earlier in the 19th century, but the camera of the late 20th century (even if not yet digital) had become an object with quite a distinct set of associations than it would have had in the 1890s. Even though Eastman Kodak was founded in 1889, the personal camera was certainly not yet an everyday object back then, the kind of thing anybody would have had available to take along when going to look at "where they lived." (Marks & Spencer, by the way, was founded in 1884.)
These traces of social and technological development put some content into the distinction between then and now made in the conclusion by the phrase "something that's blowing down the century"—it is a century of plastic and images. The very vagueness of the phrase makes it somewhat sinister, too—it is the "long twentieth century" in which the world of the 1890s was rent asunder. This undertone, combined with the wind, connects the poem with Walter Benjamin's Angel of History (see part IX of "On the Concept of History"), its back turned toward the future, its wings caught in the wind blowing from the past, the ruins of the past piling up in front of it.
But Adcock's poem is not as ark about the progression of history from past into future. There is a wind blowing, but it is "brisk," not stormy and threatening, and we are smiling (and "not callously"). And as line 2 suggests, "we" are not wholly separated from "them" by time; in fact, the poem as a whole traces the complex ambiguity of being both connected and separated at once. We do not see anything that specific when we look back, but it is also not ruins that we see. The Angel of History may be around the corner, and even the aura of Benjamin's understanding of photography might be hovering around the pictures taken in the poem, but the present is vivid here, both in itself and in its relationship to the past.
"Where They Lived" does not deny that the "something" of the last line has a sinister side, but it does not reduce the century to that. We know things they don't know, but our knowledge of their ignorance does not make their world either a ruin or even something to be nostalgic about. We are here, sympathetically aware of the past, while also enjoying the present, as the time in which we live.