He's... still stuck staring. Liir doesn't do well with surprises, even now, but after a moment he's got his wand in his hand and his green eyes are hard.
"I don't know where you got the supplies for the Polyjuice Potion," he says with a glare, "but you will tell me who you are and what you think you're up to right this instant or I swear by my position at the Ministry, I will end you."