August 1917. As the Allies launch a massive offensive on the Western front, Captain Richardson, a battlefield veteran of the trenches leads four heavy tanks on an impossible mission against the German front line. A brazen assault through the wasteland battlefield that could shatter the German defences and create an opening for Allied soldiers to pour through and hasten the end of the war. 

But when tank F41 becomes trapped in no-man-land, that battle is transformed. The men can neither advance nor retreat as the tank sinks deeper into the mud, all while shells rain down all around it. To make matters worse, the German Army is regrouping for a massive counterattack, and tank F41 is stranded right in front of them. The Germans try to force their way inside with every weapon at their disposal, and soon the tank is no longer a mobile fighting machine, but instead an Iron Fortress that is moments away from being overwhelmed. 

Inspired by the true events and people of World War I, writer Michael G. Thomas creates a thrilling tale of heroism and brutal warfare so real you can sense the claustrophobia, hear the bullets, and feel the terror. Iron Fortress tells the true story of the heroic crew of tank F41 as they do the impossible, and fight a desperate battle, alone and outgunned, in the middle of the infamous and brutal Battle of Passchendaele.