The Ghost primarily functions as symbol of the guilt that Elliot carries with him. The Ghost looks like the first man Elliot killed in Iraq, usually appearing and standing some distance away, watching Elliot and asking for his passport back in Arabic, which suggests that Elliot killed the man unnecessarily due to a misunderstanding. Although acutely, the Ghost represents Elliot’s guilt over the man he killed, it also more broadly comes to represent the guilt and shame Elliot feels about his life in general over his care for Mami Ginny, his hatred of Odessa, his dead-end job, his previous addiction to painkillers, and so on. Although the Ghost never touches or attacks Elliot of his own volition, when Elliot finally decides to attack the Ghost, they struggle until the Ghost gets hold of Elliot’s wallet and searches through its contents, further suggesting that what Elliot may have perceived as an attack when he shot the man was merely a misunderstanding. After the Ghost searches Elliot’s wallet, he touches Elliot’s face, exploring every feature with his fingertips. Elliot holds still, but terrified and seemingly making his peace with the Ghost by accepting the guilt and responsibility for what he has done.
The timeline below shows where the symbol The Ghost appears in Water by the Spoonful. The colored dots and icons indicate which themes are associated with that appearance.