Overview: During World War I, the Allies devised a devastating attack, planting 600 tons of explosives in secret tunnels driven under the German trenches. NOVA uncovers traces of the operation and why it failed to break the lethal deadlock of trench warfare.

DVD Verdict: Simply put, 'NOVA: Secret Tunnel Warfare' opens a unique window on the frenzy of Allied mining activity that led up to the attack and its bitter aftermath. Basically, and amazingly given the skill level involved, in WW1 Allied troops tunneled under enemy lines to create the biggest explosion ever seen!

As shown, and as thought, building the tunnels was desperate work, with tunnelers at constant risk from flooding, cave-ins and enemy digging teams; German sappers would listen for telltale sounds and explode counter-mines, or sometimes break through into Allied tunnels and grapple in primitive, face-to-face combat in the dark.

At 3:10 AM on June 7th, 25 mines at Messines were simultaneously triggered in what was probably the single biggest non-nuclear explosion of all time, heard clearly in London 150 miles away. 10,000 German troops were killed instantly—but the stunning success was just the beginning of another wartime nightmare.

Now, archaeologists are revealing the extraordinary scale and risks of the Allied tunneling operations in the biggest excavation ever undertaken on the Western Front. 'NOVA: Secret Tunnel Warfare' is PBS' latest NOVA documentary and one of their best, for my money. This is a Widescreen Presentation (1.78:1) enhanced for 16x9 TVs.