[spoilers] Lucas. Just Lucas.

[Byatil]

I've been watching series 7 recently, and I thought it was a nice touch that in 7.7 (I think it's that episode) when Lucas returns to Russia, RA acts in an incredibly similar way to the way he did in the car journey in 7.1. He doesn't seem to blink much, taking it all in as if he's in a dream. Superb acting on RA's part, I love the way he links little moments like that with the smallest of details.