[Slowly, he crouches next to her on the floor, meeting her eyes. He knows what's going through her head--it's not as though he didn't feel the same sort of emptiness when he'd realized (ten years, no, never again) but right now, there's someone in front of him who needs help, and so his voice is stern.]

Oona. I need you to focus.

[On him. On his eyes. On his voice.]

He is not here right now. That does not mean he is gone forever. He may yet return [but not remember anything] or we may yet find him. [in who knows what state?]

Do not give up hope.