The Dark-indigo Thundercloud is a poetic riddle intended to express pleasure with The Paralysis of Fog, originating in The Temptation of Slobs. The form guides poets during improvised performances. The poem is a single tercet. A form of parallelism is common throughout the poem, in that certain lines are required to maintain phrasing. Every line of the poem has a medial caesura. The third line of the tercet must expand the idea of the first line. The first line has five syllables. The second line has eight syllables. The third line must make use of consonance and juxtaposition. It has twelve syllables.