Metaphorical / Biblical illusion. “Valley of death” reference Psalms : 23, refers to protection provided by God which is ironic given the situation. It also symbolises the inevitability of tragedy. The higher ranks *shouldve* protected the man, yet forced them to engage in a dangerous conflict. “Mouth of hell” the story of the harrying of hell, which is when Jesus went to hell to recieve the souls of those condemned to achieve salvation, which relates to the soldiers who sacrificed their freedom for those at home.