When the Red Shield's headquarters are destroyed and Saya is believed to have gone down with it, David sinks into a deep depression and becomes an alcoholic. Hagi helps David snap his world back into focus, though, after Hagi makes an observation about David's unhappiness, and he picks up his gun and is able to fight once more.
When the Red Shield's headquarters are destroyed, Saya is believed to be lost, and David descends into a deep depression, becoming an alcoholic. Hagi helps David regain his composure by making a perceptive observation about his unhappiness, which prompts him to pick up his gun and fight once more.