W. Frederick Zimmerman gave 5 stars to: Without Warning

Birmingham Gets My Vote for New King of Techno-Thrillers, June 3, 2009

With Michael Crichton gone and Tom Clancy apparently retired (having written Jack Ryan into a corner), I have to say that John Birmingham gets my vote as the smartest writer of gripping techno-thrillers in action. This is a dazzling followup to his Axis of Time series with an even more brilliant premise. I can’t wait for the remaining books in this series.