The speaker feels connected to people everywhere. In the first stanza, her "frenzies" and "hopes" seem to live in many hearts, in streets, flats, nations, bistros and prairies. Her private feelings aren't really private; they're shared by countless strangers.
The second stanza pulls back to ordinary scenes, fields, bungalows, dogs on chains, then points to a single sky and sun, a "subtle puppetry" that quietly moves everyone. It suggests that beneath our differences, something common governs us all.
Then the speaker voices a wish: that her words could travel into prairie rooms and ship holds, murmuring a vision of ecstasy, and find kinship with prisoners, people alone, and people in crowds, each carrying a "flame." The ending imagines all those flames burning together, strong enough to destroy burdens, old city walls and even the "neural fortresses" of our own minds. The mood is hopeful, tender and a little daring, a longing for connection that could set people free.