S1, E1: At Messines in Belgium, bomb disposal specialists work alongside archaeologists on WWIs biggest archaeological dig. During the First World War this was one of the killing fields of the Western Front and 100 years later the ground is still littered with unexploded shells, grenades and ammunition. Held by the British in 1914, Messines was captured by German troops, including a young Adolf Hitler, and for nearly three years the two opponents faced each other in trenches, which the archaeologists uncover. What are revealed are trenches, which have seen the results of some very heavy fighting.