The speaker is on a train traveling north to south when another train rushes past in the opposite direction. Inside it, among a blur of faces, is the speaker's son, someone he loves beyond all others. They are close enough to pass each other, yet neither can stop, call out, or reach across the gap. The moment is over almost before it begins.
The feeling is a quiet, aching helplessness. The landscape of paddy fields, groves, lagoons and glittering pearls sounds beautiful, but it only slips by, and the speaker barely seems to notice it. What matters is the missed connection. The ending carries the poem's sharpest image: the speaker's body goes one way while his heart rides the other train in the opposite direction. The mood is wistful and tender, and it hints at how easily the people we love can drift past us, even when we are almost within reach.