He looked at Honor, and his expression turned much more serious.

Her expression turned serious at the mention of the box.

She stared at him a moment before her expression turned dark.

His expression turned thoughtful as he considered for a moment.

She looked down at herself and her expression turned to disbelief.

When he was close enough to recognize her, his expression turned to surprise.

He leaned into the table, his expression turning very serious.

Her expression turned serious as she squinted into the night.

Before he can even leave our table, her expression suddenly turns more somber.

His expression had turned serious and the least bit strained, as though waiting for my reaction to what I'd been told.