Sitting quietly and wishing to be left alone, the speaker watches a group of people draw closer, and the poem follows their rising anxiety. At first it is only a wish for silence, but the "swarm" keeps creeping nearer, and the speaker's calm starts to crack. Their screams stay "internal," so nobody around them knows how frightened they are. The speaker even calls themselves "a plague" and "a disease," which suggests they believe other people ought to avoid them, and that makes the group's presence feel more threatening and confusing.
Panic builds as the speaker imagines the group is plotting something. Judging by the imagery, the laughter that follows them out may be innocent, but to them it feels cruel. Then the mood shifts. Looking back, the speaker scoffs and the fear is gone, replaced by a floating sense of freedom. The short, trailing lines create a tense, jittery feeling, and the ending is calmer, though it also carries a note of isolation: "that is how I shall stay."