The original book of this was set in the 1950s but that won't do for the TV series because most people watch for the 1930s style. Ironically the tube train near the end was a 1950s train painted to look like a 1930s train so the Underground can play at that game too. Hanging the storyline on a plot about the Jarrow March was feeble but the 50s version had students who were beginning to think about the world around them so I suppose making them think about the poverty of the marchers is much the same thing. All the stuff about Japp having to cater for himself was weak too but they had to put something in to fill the time. This would have made a decent half hour show or they could have filmed the book and made it a better long show. It is obvious this episode is a victim of style over content.