Barney thinks that most people only have one purpose in life, and that is to make his own life as difficult as possible. People such as loan sharks, policemen, policewomen, traffic wardens, people who work at recycling centres, cyclists, every woman he's ever tried to have a relationship with, and a horse. But most of all, people who use vending machines.
He works as an engineer, but his confrontational nature leads him into verbal conflicts with rude or irrational customers, and also with his boss.
Alison is his work colleague, who has genuine reasons for thinking the world has been unkind to her. She has just escaped from an abusive marriage, and is beset by health problems. She has no friends, except Barney.
But he has problems of his own. He owes a lot of money to some bad people, and he is nearing breaking point at work. His boss is waiting for him to go too far and can then have an excuse to fire him. If he doesn't get killed first.