The speaker has heard of a Chinese ritual in which people burn objects so that the dead can carry them into the afterlife. Moved by the idea, they imagine doing the same with every poem the two of them once exchanged, written by the speaker for the person they lost and by that person for them.
But the speaker is honest about doubt. They don't believe the smoke will carry anything anywhere. Their reasoning is that ritual "contains more meaning than truth can retain": a gesture can comfort us even when facts can't. The ending turns on that tension. Wanting to burn the papers is one thing, and daring to is another. The speaker can't bring themselves to let the words disappear.
The mood is quiet, tender and torn. Short, broken lines make the poem feel hesitant, as if the speaker is stopping to think mid-sentence. Grief here is both the urge to send something to the dead and the fear of losing the last physical traces of them.