In a nutshell: Trail of Chthulhu... after the End.
Sadly i didn't like this book. My biggest issue is that when i bought it, i -- perhaps mistakenly -- expected a series of ToC scenarios set in post-apocalyptic setting. However, there are no pre-made scenarios in this book; not even campaign frames like those in main ToC rulebook. There is a half-decent section on creating your own customised apocalypse and a short and too-vague GM advice section.
My second complaint is that this book is short -- only 73 pages and fully half of those are taken by standard ToC rules tweaked to post-apocalyptic setting. I've seen it all before in my ToC core book and i don't need to see it again, thank you very much.
But enough on the negative.
Like all other products by Pelgrane Press the writing is top-notch, well organised and full of great ideas. In short summary: the sanity system is slightly tweaked; there is a section on how cities decay into ruins with time; also a very useful system for scavenging equipment; an obligatory chapter on mutants; and of course the Apocalypse Machine itself -- scenario generator that lets you customise your own extinction event.
As a side note, i think this book would be useful for GMs running "Armitage Files" also by Pelrane Press as the subject matter is similar.
Unfortunately all that is not enough to raise this product from mediocrity and i cannot in all honesty give it a higher rating, though i really wish i could.