More terrible than terror...

Étaples was a particularly notorious base camp for those on their way to the front.

Under atrocious conditions, both raw recruits and battle-weary veterans were subjected to intensive training in gas warfare and bayonet drill, and long sessions of marching at the double across the dunes. After two weeks, many of the wounded would rather return to the front with unhealed wounds than remain at Étaples.


But the context cannot be better described than by poet/soldier Wilfred Owen, resting in Etaples on his way to the line:
"I thought of the very strange look on all the faces in that camp; an incomprehensible look, which a man will never see in England; nor can it be seen in any battle but only in Etaples. It was not despair, or terror, it was more terrible than terror, for it was a blindfold look and without expression, like a dead rabbit's."