No deal Brexit with entirely man made consequences leading to lorries piled up at ports, lack of food at the Supermarkets, and people dividing along remain/Leave lines to blame each other for the mess. Lack of medications, petrol etc. I didn't learn until recently that a lot of the petrochemicals used in the UK come through Rotterdam - that will mean if arrangements for exporting/importing fuel are suspended we'll be in trouble fast.
I am lucky that living in the country near a lot of farmland I would probably be able to get hold of fresh vegetables... but who knows? If people have fuel and are offered a lot of money maybe not. I've always had emergency stores, but I'm thinking of ramping that up, finances permitting, which they don't at the moment.
The UK already is under unreasonable government - the poor are being starved, there are increasing numbers of homeless on the streets and living in precarious accommodation. and lets face it, no bloody government could look at the prospect of Brexit and think it's a good idea for the country, not least for the possible effect on Northern Ireland. People are too tired to rebel at the moment, but throw in some food shortages and problems with getting fuel and medication and I think we could be very close to a breakdown of society. It seems ridiculous to me that people prefer these Tory bastards to the possibility of a few people claiming benefits who might not deserve them... I know I hate how hostile and self-centred our society has become, and I think that leaves it vulnerable to all sorts of ills.
Basically this doesn't feel like fantasy over here, it seems a distinct possibility and it scares me.