Doctor Who Series 10: 14 Easter Eggs & References You Might've Missed In 'Smile'

10. The Vardy

Though they were referred to simply as Emojibots in the promotional material for this episode, in Smile itself the robots are called the Vardy. This is an in-joke on the part of writer Frank Cottrell Boyce. Professor Andrew Vardy, of Canada's Memorial University, studies swarm robotics - much like the microbots that form the city. Vardy is a friend of Boyce's and they once co-wrote a short story together.

Microbots have appeared in many modern Who stories. Most notably, nanobots were the reason for the gasmask plague sweeping through war-torn London in 2005's The Empty Child/The Doctor Dances (written by current showrunner Steven Moffat).

Elsewhere, the Doctor attempts to blow up the Vardy's city by overloading its cold fusion reactor. You can glimpse the name 'Fleishman' written on the machine in some shots. This is presumably a (misspelled) reference to Martin Fleischmann (1927-2012), who was a pioneer of research into cold fusion.