"One of the... Doctor, it is simple physics. It's the solid state of water created when temperatures drop below a certain threshold. How can be be a 'splendour of nature.'?"

And he thought he could be overly scientific about things. But then she sees him skate away to pick up snow, just as he says 'snow war' and she gets concerned.

Her voice is hesitant. "Doctor...? What are you doing?"

She's so concerned that she misses the last sentence. She skates closer to him, because well, he is always safe, right? Even when he's reckless.