Nick and Herbert are brothers with no so good parents who left for Australia.
Herbert is dumb and a comic relief.
Nick is the young of the two, 13 and smart. Street smart not book smart.
A client came in the door and paid them 500 pounds for keeping a package for a week.
The client was a dwarf who was later killed.
The mystery begin with the gangster Fat Man threatening the older brother.
Another gangster has recently died leaving a treasure that nobody could find. It is a treasure in diamonds.
The brothers were being called by the Fat Man. The package that they kept were the key to this treasure.
But when they opened the package, it is a box of Malteser.
The writing is humorous. A light and enjoyable read. Very suitable for young persons and the plots are not too grown up.
The advantage of being young is that they could go through window and escape tight places.
This is written long ago. Before mobile phone and computer being a common household item.
Still. It is a good read.