"She worries about you," River says quietly, her steady gaze looking right through him like nobody else can, and Mal's answering smile is tense.

"She ought to know the worrying's my job."

She shakes her head. "That's not how it works." Mal feels frozen as she pushes herself up onto her toes and presses her lips against his cheek, sure that he should move away and incapable of making himself do it. "But it's okay. We'll worry about each other."