Ahh, Charlie's portal fantasies. In air quotes.
I bought the first 6 in hardback. Then the re-worked, re-issues on Kindle. I have been absolutely having a blast with the new trilogy.
Stross uses the tired old portal fantasy trope to hold up a dark mirror to our modern world. This one has multiple dimensions and time lines, ex-Stasi sleepers, nuclear armed socialist democracies and a USA that if anything, seems less scary than the current version. When the author tried to make it more scary!
A thoroughly satisfying read that is only getting a 4 because it suffered a little from 'middle book in a trilogy'. No plotline wrapped up and you just want to get at the rest of it by the time you reach the end of this book.
Recommended!