Perhaps appropriate for a poem that recounts a hallucinatory dream vision, the tone of “Kubla Khan” is unsettling. The poem’s unsettling quality first makes itself felt in the second stanza, where the speaker describes the sacred river’s place of origin in decidedly occult terms (lines 14–16):

A savage place! as holy and enchanted
As e’er beneath a waning moon was haunted
By woman wailing for her demon-lover!

Other occult elements return at the poem’s conclusion, where the speaker envisions a second pleasure-dome haunted by a terrifying man with “flashing eyes” and “floating hair” (line 50). These visions are unsettling in the sense that they involve the speaker perceiving occult phenomena that aren’t actually present. In other words, the speaker is experiencing a dreamlike hallucination. Coleridge echoes the unsettling quality of these hallucinations in the unpredictability and fragmentary nature of the poem’s overall form. For instance, the poem frequently shifts between lines of tetrameter and pentameter, creating a subtle sense of instability despite the underlying iambic rhythm. A similar feeling of instability emerges through Coleridge’s highly irregular use of rhyme. Finally, just as a hallucination might appear out of thin air, Coleridge will suddenly indent whole sections of the poem, creating jarring formal contrasts without apparent reason. These thematic and formal elements all contribute to the poem’s unsettling tone.