Along with his allies, Gaunt is trying to get out of this mess but it is apparently not possible because there are enemies on all sides and they aren’t visible. No one knows where the enemy comes from and all they see at the end is the dead body of their friend.
The way out presented to Gaunt is far deadlier but he is left with no other option. Thus he accepts this suicidal mission and from here on the real story starts. It is like walking towards destruction with no shield in hand. Initially, everyone thinks that Gaunt has made a mistake but actually he has an idea in his mind which can make them able to escape this hell like place.