The clue is in the title. This is the tale of Mr Gum, a very bad man. In fact, Mr Gum is worse than bad.
Mr Gum is the most loathsome, malevolent, foul-tempered man in the world. He is hated and feared by both adults and children, but he has his uses.
When parents want to punish or frighten their naughty offspring, they tell them Mr Gum will come and take them away. The very mention of Mr Gum's name is enough to make the worst-behaved child obey their parents.
Mr Gum lives in the small town of Lamonic Bibber. All the townspeople avoid him like a disease. But that is the way Mr Gum likes it. He hates people and doesn't mind that people hate him.
He lives in a house that is crawling with insects and smells like a sewer. Mr Gum is so disgusting that he has never made his bed and he sleeps on a mattress covered in mould and insect droppings.
Why would anyone want to read a book about a person as awful as Mr Gum? Author Andy Stanton gets all the revolting details of his anti-hero over with as soon as possible and then quickly moves on to the story he has to tell.