Last Winter is, on the whole, a well written thriller dealing with the ever popular subject of the war on terror. It even tries a new approach by having as its central villain not a crazy islamic terrorist but a traitor in the midst of the very forces tasked with defending the USA.
Unfortunately this original approach also proves to be the source of Final Winter's greatest weakness. Whilst there is nothing wrong with the idea in itself, the problem is in the execution. By choosing to have one conspirator, working alone, yet implementing a plan that is fiendishly complex the author stretches the limits of what is believable. It requires a massive suspension of disbelief in order to accept that one person could successfully organise the plan they put in motion.
If the rest of the book were similarly fatastical this wouldn't necessarily be a problem, but with the remainder of the plot striving for versimiltude the key plot twist seems all the more unbelievable. This is a situation which only worsens as additional facts are revealed to the reader, until by the the end it becomes impossible to suspend disbelief and the whole story begins to sag under the implausibility of the central plot.
Brendan Dubois is a talented thriller writer, as his previous books 6 Day and Betrayed prove. He also has a solid track record with the theme of betrayal, which is common to both of these earlier works as well as Final Winter. In the latter case however, it is the handling of the betrayal that harms what is an otherwise entertaining book. Pity.