Geologist

He turns up as a local expert on one of the pair's stops, brought in to talk rock formations and landscape history while Coogan and Brydon needle each other in the background. Practical and matter-of-fact, he treats the outing as a genuine piece of fieldwork rather than a comic backdrop.

The joke of the scene depends on his sincerity: he explains the geology straight, unaware or unbothered that he's flanked by two comedians turning everything into competition and impressions. That flat, documentary-style delivery against their improvisation is what makes the moment land, a small dose of the real world dropped into the bit.