In short: Ashen Winter by Mike Mullin is a strong sequel that takes a very raw and realistic look into humanity in the advent of a terrifying post-apocalyptic event. 
 Six months after the supervolcano has erupted, plunging North America into darkness and a deluge of ash, Alex and Darla are still struggling to survive in a frozen and crime-ridden world in Ashen Winter. The ramifications of such a destructive, post-apocalyptic event are on full display in Ashen Winter in all its gruesome and cruel glory. This is something that Mike Mullin excels at: he presents a raw and realistic look into humanity akin to The Road, that showcases the lows that people would sink to survive. It is absolutely believable and that makes it all the more terrifying. 
 Alex remains one of my favourite male protagonists. He is an inherently moral and noble character. Almost to a fault really, as there is admittedly not a whole lot of room for kindness and generosity in such a cruel post-apocalyptic world. But that is why it is so impressive. Time and time again, when faced with the prospect of screwing someone over to his advantage or treating them fairly to his disadvantage, Alex always does the honourable thing (much to Darla's chagrin). In a world full of people who do unforgivable, disgusting things, Alex at least never compromises his morality. 
 My only problem with Ashen Winter is the same as it was for Ashfall: there is an excessive amount of details in Mike Mullin's writing style, making for an unnecessarily long read that could have been edited and made shorter. Despite the elaborate writing style, I can't deny that I was never bored while reading Ashen Winter. Mike Mullin somehow manages to achieve almost literally non-stop action scenes over the course of the 576 pages. Now that's impressive. 
 Overall, Ashen Winter is a strong sequel and is definitely recommended to all fans of Ashfall. Ashen Winter will be released October 16, 2012 by Tanglewood Press, with the third and final book to follow in 2013.