He'll apologize for having overstepped based on rumours... though he hopes that, if they're true, that Cassia turns out all right in the end.

Jaskier will thank her for the information; he does think it's important, since that's highly unusual indeed for someone prepping for a show. He'll then ask after Cassia's wellbeing, as he had not heard of her current condition.

While Jaskier himself cannot communicate with birds he didn't create, he does "speak" to his own birds. The raven on his shoulder will attempt to speak to Firewing, if possible, to ask if Firewing has seen anything regarding Cassia or Umber.