A/N: I wanted to end this on a more hopeful note. I can't wait for the December episodes to air, but I'm also scared...

"What is dark matter anyway?" Penny asked, leafing through one of Sheldon't books like one of her cosmos.

Sheldon looked up from his whiteboard, startled to see her here. Didn't Penny ever leave? "Well," he said then, searching for the shortest words in his vocabulary. "Dark matter is invisible mass. You cannot see it but you can measure its effect on everything else."

"You don't get to see it but you see the effect it has on everyone?" Penny repeated.

Sheldon nodded. You don't get to see her but you see the effect she has on everyone. She matters. Still.