As the interactions between Derek and the women move forward, the words "blue" and "kettle" are inserted into the dialogue with increasing frequency, seemingly at random.
Some variants appear to be wish-fulfillment on the part of one character or another; some seem to represent a collective attempt to settle on a mutually acceptable compromise account; some include random intrusions from, for instance, a group of armed paramilitaries or an angry emu.
The women believe him and find ways of "confirming" his story, while Derek keeps them slightly uneasy and ultimately, he hopes, prepared to buy him into their lives with gifts of money – this fraud is his aim.
"[10] Sally Hales of Exeunt argued, "There’s no doubt Blue Heart is a challenge but, unlike other self-consciously intellectual literary efforts, warmth and humanity pervades Churchill’s work, no matter how weird things get."
The critic billed Heart's Desire as "both one of the funniest short plays ever written and a reminder of the savagery that often lies beneath the surface of family life.
"[13] Paul Taylor of The Independent gave the performance the same rating and praised the experimental twist of Blue Kettle as "brilliant", writing that "Churchill makes the situation all the more haunting and queasily comic by showing how language breaks down under the emotional strain creating the weird verbal tic described above.
"[14] Lynne Walsh of Morning Star wrote, "To play with a simple storyline, creating the surreal one minute, the opposite the next, a writer has to have a sure touch and know how to harness the anarchic elements and Churchill certainly has those qualities.