This is a book about the craziest inventions that didn't quite happen in the Second World War. It's based on a series of columns Parsons' wrote at Something Awful a year or three ago.
It's a fun read, with a good selection of crazy ideas. For each one, there are a few pictures (including some nice colour plates), a description of the actual history, a discussion of the technical aspects and how well it might have worked, and finally a hypothetical history if the invention had gone ahead and fictional vignette about that.
Parsons' writing is good, although he often drops into an over the top style that will be familiar to Something Awful readers. In some places, this seems inappropriate to the material. The fictional vignettes are also somewhat redundant - I feel like more attention to the analysis of the inventions and hypothetical histories would have been more rewarding to read.
All that said, overall it's great fun - covering everything from Nazi nukes to personal backpack helicopters and 2000 ton tanks.