Shearsmith

Dr Shearsmith was a resident of Crook Marsham. He and Jack Prudhoe were the first two people to disappear from the village after the Sentience began to fully manifest in December 1968. (PROSE: Nightshade; AUDIO: Nightshade)

Behind the scenes
Shearsmith is likely a reference to Reece Shearsmith, one of Mark Gatiss' co-creators and co-stars in The League of Gentlemen, whom Gatiss mentions in the afterword to Nightshade.