Dave Bonta pictures a crowd of doors, all standing open toward the light, and compares them to books that people speak into. It's a strange, quiet image. The doors seem almost alive, like mouths waiting to say something, or like witnesses, as the title suggests. Nothing is said about where they stand, so the poem leaves us to imagine a place that has been emptied or damaged.
Then the poem turns to a bookseller who has died of grief after losing his stock in a fire. The speaker doesn't tell us how to feel, but the phrase "poor man" sounds tender and sympathetic. Judging by the way the two images sit together, the open doors may be all that remain standing, silent records of what was lost, much as books hold what people say. The mood is hushed and elegiac: sad, but restrained, with loss felt through small, odd details rather than outright statement.