His shock and uselessly defensive retort are deeply vindicating and she advances further, her fury coiled like a spring. But instead of being sufficiently shaken to give her an answer, now it's his turn to leave her staring in disbelieving outrage at his words.

She still doesn't understand how he can think that she's not making any efforts to leave this universe, how he can think that he has a say in it, but that is so very secondary to the sheer audacity and repulsiveness of his arguments. She's heard this before, all Cast off your chains with my help, friend TARDIS, and the memory sets her nerves thrumming with hate. His final insult, then, is the last straw; she absolutely abhors when he does this, pretending as though there was some sort of kinship between them.

So her fury uncoils in one swift slap, hard enough to leave her hand stinging. In the same moment the flow of Time between her two shapes spikes drastically; an effect of her physical form's proximity to her true form that she hadn't even been aware of, forceful like currents between magnets. "We are not the same," she hisses, "not since the Foundry's fires scorched every last atom of yours out of me! And how dare you think I would need you to escape? I am the only force here capable of breaking out, and I will do what you never can, and you will be left behind as always, because I will not be of use to you." Before she's even done giving voice to her outrage, she grabs the front of his shirt and pushes him back with all her strength.