"Do you think if I interrupt you, would you stop out of politeness? It might be easier than... whatever you just did."

Penric could have Desdemona speed up his own reactions... somewhat, for a limited time. They were both bound by human anatomy, regardless of how fast Des could react.

Though we finally found someone who talks more than you, Pen. Des's mental voice was kidding. She was still trying to form her own impression of this new person as her human rider did.

Penric, meanwhile, was interested enough in this compulsion to experiment. A bit like the weirding voice shamans could call on (and he could duplicate and a greater cost), but apparently natural.