Mattheusz talks about C.S. Lewis' Narnia stories. Narnia and the Whoniverse have many connections, starting with the TARDIS, which some sources report as being based on the Wardrobe. Tom Baker, who played the Fourth Doctor on Doctor Who (1963), played Puddleglum in The Silver Chair (1990). Warwick Davis played multiple roles in various Narnia movies before playing Porridge in Nightmare in Silver (2013). Other actors who have been in both a Narnia project and a Who project include Maureen Morris, Richard Dempsey, Camilla Power, David Walliams, and Simon Pegg. One Who project was titled The Doctor, the Widow and the Wardrobe (2011).
The plot is similar to the American teenage nostalgia movie The Breakfast Club (1985), but with aliens added in.
This is a "bottle episode" which is often done by high-budget franchises as a breathing space. It cuts cost by reusing existing, minimal set pieces, and eschewing any guest appearances.
This is one of a few episodes whose title does not parody a popular book, movie, or song. Another long running science fiction franchise had an episode called Detained (2002), but the two episodes do not resemble each other.
This episode takes place in November 2016.