Jayne's up instantly, firstly, well, because, tussle. Secondly, he got his marching orders. And as much as he and Mal got their differences, marching orders are marching orders.

Duck--

Dang, she's fast.

Shift your weight, good thing eats've been slow comin' lately what with the lack of employment; that extra ten pounds would've meant a broke brainpan right about now--

River bends impossibly, leg high, head low, and the last man between them falls, and Jayne catches her--

"Gorram it, girl, it's me."