Tarn dips the rag deeper as Spinister tilts his head, working on a spot as far down as his thick fingers can reach.

Spinister falls strangely silent and for a moment Tarn thinks that perhaps he's already done something wrong. But, judging by the way the rag hangs in his limp hand, he rather thinks that it's the opposite

This is preferable. At least he's stopped grumbling and decided to be agreeable for once.

Tarn catches himself wondering where else could clean that would keep the heli in such a state of sleepy bliss.