Black Plaques are not to be found proudly mounted on a wall - and for good reason.
What with their commemoration of a brutal execution outside Westminster Abbey, the selling of sex toys in St James's Park, and an intruder at Buckingham Palace with Royal undergarments stuffed down his trousers, this is not the sort of historical subject matter authorities choose to grace a building's facade or depict on a visitor information board.
In fact, many people might hope such indecorous and inconvenient episodes remain quietly overlooked.
But this book jogs such artful lapses of memory and at one hundred and fifty locations across London, Black Plaques lift the carefully placed rug to discover a big stain.
The unseemly blemishes brought to light recall moments when mankind was not enjoying its finest hour, so there are scenes every reader should find disturbing.