A startled breath huffs out of him, carrying with it something that might be a ghost of laughter's distant memory.

"I'll try. I promise."

He squeezes her hands, careful to not exert too much pressure, and straightens, looking down at her. He doesn't smile, but there's something quiet and even fond about the look in his eyes, just for a moment.

"Take care, Agent Carter. I'll come see you again."

Someday. Maybe. If he can.