Christmas 2014 and dead bodies are littered outside the barbed wire at the base of a giant wind turbine, a half-dozen cold-eyed National Trust guardians with shotguns standing over them. Some 99.99 per cent of humans on earth have died, in the great plague of mid-2014, and the survivors are desperate for access to what remains of the past.

This, roughly, is one possible setup – he doesn’t go into the details – for Lewis Dartnell’s quite remarkable new book. By showing what technology would be needed ‘to rebuild our world from scratch’, he neatly highlights what hidden knowledge we constantly depend on, how fragile it is and how very much we should respect it. 

The first few months are crucial, for that’s when the most important leftover resources will still be available: diesel fuel that hasn’t yet clogged up underneath petrol station forecourts; electricity generators that can still operate without impossible-to-order parts for repairs. Prisons outside major cities, Dartnell points out, would be excellent