Out went the taper as she hurried in; Its little smoke, in pallid moonshine, died: She clos'd the door, she panted, all akin To spirits of the air, and visions wide: No utter'd syllable, or, woe betide! But to her heart, her heart was voluble, Paining with eloquence her balmy side; As though a tongueless nightingale should swell Her throat in vain, and die, heart-stifled, in her dell.
The atmosphere thickens even more: the light goes out (of course, of course) just as Madeline comes in. In a grim turn, it's described metaphorically as dying. So far, so bad.
Madeline has to be totally quiet if she wants the ritual to work, but she's so keyed up that she can hear her own heart beating ("voluble" means "audible" here).
Even though Madeline keeps getting described in these otherworldly terms, the poem also keeps on making a big deal about her physical body: she's "akin / To spirits of the air," but most of the language in this stanza is spent talking about her pounding heart, her panting breath, "her balmy [sweaty] side."
The predator-prey language we got a glimpse of in the last stanza comes back, this time with way more creepy: the last two lines here refer to the myth of Philomel. Philomel was this totally innocent woman who was raped by her brother-in-law, who then, to prevent her from telling everyone what he'd done, cut out her tongue. At the end of the myth, Philomel gets turned in a nightingale.
Romantic, right? Do you think it's kind of odd that, at the moment when our power couple is finally united (well, sort of united—Porphyro's still hiding), Keats chooses to remind of us a famously gruesome tale of rape? Yeah. We thought that was weird too.
Also, if we're going to think about the Philomel myth as a metaphor, how do you think that metaphor's working? This one's a doozy—it feels as though Madeline has taken on the symbolic force of Philomel the Woman Anticipating Rape, Philomel the Fleeing Nightingale, and the Thing That Can't Get Expressed (that is, the report of Philomel's rape, or in Madeline's case, all the stuff she's feeling as she enters her bedroom, but can't express). Like we said: this is a doozy.