Testing.

Yep, that's what he is always doing. All of the time. Testing River's health. Testing Wash's humor. Testing Jayne's temper. Testing Mal's patience. Testing Kaylee's… Kaylee. Hwoon-dahn! The name he calls himself. Why does he do it? She doesn't need tested.

He's testing River now. The needle goes into her arm and retreats with a sample of her blood. Her eyes stare him down.

No. She's doing the testing. She knows so much. Too much. How? Some condescending words escape his lips. She rolls her eyes, tells him he's stupid. Wants to get back to the important conversation they were having silently. She does it all without a word. He's just her daft older brother with no common sense. He doesn’t speak aloud again. But she answers his unthought questions. She knows his stupid tests. She answers with her eyes.

Don’t.

Then,

Do.

He stops then. Putting the answers with the questions.

Don’t test.

Do respond.

Mal's head appears around the door frame. "What're you doin'?"

"Testing."