Lanchester builds on the absurdity of Trump’s impenetrable wall to prevent immigration. He conceives of a wall around the British Isles. Naturally a wall isn’t enough. It must be defended, as all walls must be, which consumes enormous manpower. That manpower comes from a type of National Service. The British mainland coastline is 11,000+ miles everyone one of which must be defended. Clearly there are hotspots but a defensive system is only as strong as its weakest link.

The logistical horror of defending 11,000 miles of wall isn’t lost on anyone. A 24/7 operation. Relying on patriotism isn’t enough and so Lanchester erects a wonderful incentive scheme. For every breach of the wall that number of illegal immigrants will be replaced by defenders.

‘You let one in and you go over the wall never to return.’

This marvellous novel has numerous sub-plots all of which enhance the storyline. It’s bleakly dystopian and very much a book for our time.