He stared as Zuko left, wondering what his nephew was doing? Giving up? Getting assistance? Venting his anger on something? Hunting the Avatar? With Zuko, one never knew.

While he was considering if he should go after the boy, or allow him some time to cool down, the device - the phone - started making noise. Um.

He took a sip of tea, got up carefully, went to the front door and unless he could see Zuko just by doing this, would call out, "Zuko! The thing is making noise!"