A commentary for the series 3 episode Blink, after the usual protracted preamble.

The book John likes is Riddley Walker by Russell Hoban, available from all good and wicked bookshops. We like the ones who pay their taxes best.

https://www.waterstones.com/book/riddley-walker/russell-hoban/9781408832240

The brilliant book podcast that has recently covered Riddley Walker is the Backlisted Podcast:

https://www.backlisted.fm/episodes/9-russell-hoban-riddley-walker

Una McCormack is in it, and she's one of us.

Lawrence's recommended time travel books are the Lightbringer Trilogy:

https://www.fantasticfiction.com/l/samantha-lee/lightbringer-trilogy/

The film John chunters on about is Christopher Smith's excellent horror movie Triangle:

 https://www.rottentomatoes.com/m/1212111_triangle

 And the film in Smith's oeuvre that John can't quite bring to mind is the excellently silly horror comedy Severance.