They are the most remarkable pictures of one of the most hellish places on earth. Never seen before, these astonishing photographs, lovingly hand-touched in colour to bring to life the nightmare of Passchendaele, were released this week to commemorate the 90th anniversary of the battle that, between July and November 1917, claimed a staggering 2,121 lives a day and in total some quarter of a million Allied soldiers. Killing field: A German machine gun unit strafes No Man's Land at Passchendaele as artillery shells churn up hte ground and mustard gas billows over the front What was once pretty countryside...