Critic Harold Bloom refers to this short poem as "one of Blake's gnomic triumphs." The speaker addresses a rose, which he claims is sick because an “invisible worm” has “found out thy bed/Of crimson joy.” The rose symbolizes earthly, as opposed to spiritual, love, which becomes ill when infected with the materialism of the world. The rose’s bed of “crimson joy” may also be a sexual image, with the admittedly phallic worm representing either lust or jealousy. The worm has a “dark secret love” that destroys the rose’s life, suggesting something sinful or unmentionable.
Nature brings this sickness to the worm with “the howling storm.” Although the speaker decries the rose's sickness in the first line, the rest of the poem subtly suggests that the rose is not innocent of her own destruction. The worm has incidentally "found out" the rose's bed, which is "crimson joy" even prior to the worm's arrival. The red of passion and of the vaginal "crimson bed" image counterpart to the worm's phallic one suggests that the rose has already been experiencing some kind of lustful passion.
In keeping with much of the Songs of Experience, this poem is brief, with two stanzas, and deviates from the Innocence rhyme scheme of ABAB CDCD. Here the rhyme scheme, ABCB DEFE, introduces a note of discord in keeping with the ill effects of the "secret love" which the rose hides, much to its detriment. "Worm" and "storm" are rhymed, connecting the agent of destruction with a force of nature. In the second stanza, "joy" and "destroy" are connected, linking what should be a positive experience to the decaying disease that the rose has contracted.