See in text (Text of the Poem)
The word “insane” operates as both an adjective and a noun in this line because of enjambment. Enjambment is a poetic device in which a sentence continues beyond the end of a line and can be read meaningfully both to the end of the line and to the end of the sentence. When read to the end of the sentence, “insane” is an adjective that implies that the woman is not of sound mind. When read to the end of the line, “the insane” is a noun that refers to all people who are defined by their state of madness. In this meaning of the line, she is led by a group of people rather than her own madness.