With a dead sound on the final stroke of nine.
TL;DR: Most interesting to me is the mirrored structure which exists both thematically and structurally within this section—and within all its references. At first glance I thought it might indicate a doubling or twinning of sorts; but I’ve now understood this “mirror” to be more of a replication (or regression).
Midway through the stanza comes the line “With a dead sound on the final stroke of nine.” Upon my initial reading two significant features revealed themselves. First, there is numerical weight to the chosen number “nine.” In Baudelaire's poem the unnamed narrator watches seven old men, all identical in misery and form, tread somberly before him, before at last arriving at the terrible understanding that he himself is the “awful eighth.” And so of course the natural progression is to uncover a ninth member in this hellish parade; and obligingly Eliot supplies us with one. The ninth is, of course, himself, or perhaps the reader; either way the mention of the number “nine” suggests that this repetitive pattern has not yet ceased. In the original Les Fleurs Du Mal, Baudelaire plays with the notion of what I initially thought was doubling: there is the “spectre” of self which walks and speaks in our “city full of dreams,” the hypocritical Reader decried as Baudelaire’s “second self—[his] brother,” and, of course, the seven (or eight) old men, whose presence compels the narrator to double back and flee home. But at the very end there is a line which suggests that—as I’ve come to realize—that this doubling is more of a regression: “In vain my reason tried to cross the bar,/ The whirling strom but drove her back again”. And so in this way Baudelaire introduces another creation story for the ‘doubled’ men, in which they are not copies of one another but one and the same, forced back along the same path after having failed to “cross the bar”. So what is this “bar” which cannot be crossed? Eliot appears to suggest it is death itself. It seems to me that “a dead sound on the final stroke of nine” is operating as a threshold of sorts, or the “bar” in question: the line cleaves the stanza into two exact halves, each of which can be considered a “double” of the other. In this way it becomes clear that the “doubles” we are dealing with are the stanza’s halves, each of which depict an eerily similar motif. The first half of the stanza (lines 1-8) pays homage to Dante. The line “undone by death” comes from a section of the Inferno in which Dante meets the Uncommitted, a group of souls who reside neither in hell nor out of it. But interposed over this image of dead souls in limbo is the living, since Eliot roots this classical reference in a visual description of modern London. And so through this overlay Eliot melts any barrier between the living and the dead, perhaps suggesting that they are one and the same (a suggestion, it is worth noting, somewhat loosely put forth in De Nerval’s dream writings). The second half of the stanza is much the same. Eliot introduces the image of the deathly bloom, where the narrator expects mysterious flowers to erupt from planted corpses. This description seems to be most obviously an allegory for the afterlife: flowers growing from corpses are, after all, a continuation of life after death. But interestingly, the afterlife appears to be inaccessible. The lines “'Or has the sudden frost disturbed its bed?/'Oh keep the Dog far hence, that’s friend to men,/'Or with his nails he’ll dig it up again!” suggest that small discrepancies are capable of disrupting our entire future (which, again, is the plot of De Nerval’s writings—he spends the entire excerpt ranting about how our lives are the sum product of infinitely small moments and knick-knacks); and the questions marks suggest that as a result of these discrepancies, the flowers’ ability to bloom, or our ability to access the afterlife, has been compromised. Looping back to Baudelaire’s model of duplication—in which doubles are produced by a ‘doubling back,’ or re-walking of the same path—we can see how the stanza’s halves inform our understanding of the poem as a whole. Both parts reference our inability to move into the afterlife: the first half speaks of life and death as another doubled pair, implying that the dead souls ‘double back’ onto the living (aka they hit a dead end, cannot move past into the afterlife, so turn around and go back into the realm of the living); and the second half’s tie to the continuation of life post-death has already been thoroughly explained. This understanding gives new resonance to “a dead sound on the final stroke of nine”. Yes, the line references death as a threshold; but importantly, it frames death as the “bar” we fail to cross. There exists “a dead sound,” suggesting a sudden impact or some unsuccessful attempt. I think what Eliot is trying to say is that nothing ever changes; having died, we fail over and over again to access the afterlife, instead ‘doubling back’ onto life. As a consequence all future generations become copies of the past; and we get this weird circularity that Eliot flirts with for the rest of the poem.