When a baby faced, weak girl the exact age that Beloved would have been comes knocking on their door, it is debatable as to what or who she is. She may be a Jesus figure, a devil, a terrible coincidence, or even the physical manifestation of the murdered child. The most accurate explanation may be that she is a blend of all of these possibilities. Whoever she is, this ghostly presence is most of all a catalyst for change. She puts Sethe's repressed feelings of abandonment and fear out into the open. She pushes Denver out of the ambition-draining tomb she has lived in all of her life and into the cold hard light of day. She pushes the truth about what Sethe did out of 124 and out where everyone can see. So that Paul D can realize it, retreat, and come back again with a whole new willingness to help Sethe. Beloved wants to be remembered.
Without deciding whether or not Beloved is truly a redeeming character, it seems that she does end up being the catalyst for change. Her insatiable desire to be remembered ends up helping the household of 124 in the end. Having Beloved not be forgotten allows the community back in and allows Paul D back into Sethe's life. A similar case in which a ghost is the means to a new ending is King Hamlet in Hamlet by William Shakespeare. Appearing to his son one night and asking for revenge against his brother for both murder and the stealing of his wife, he is, in his own way, asking for remembrance. He is asking that his story not die in the grave with him, but rather be resolved by his son.
In his article, "Hamlet's Ghost: A Review Article,"(http://www.anthropoetics.ucla.edu/ap0701/hamlet.htm) for Anthropoetics 7, Peter Goldman asserts that "The primary imperative of the Ghost is to "Remember," not to "Revenge," as commonly thought." This reinforces the idea that thinking of these ghosts separately from a positive or negative stance, their main functions are to initiate change. It is from here that the two stories take very different paths. The characters in Beloved end up better off for the truth being out in the open, and those in Hamlet die in a revengeful bloodbath. However, in both cases, the motive of the ghost figure could be interpreted superficially as revenge. It does appear, when the red light floods Paul D at his arrival to 124, that the baby could be purely an angry force. However, the relationship of the ghosts in Hamlet and Beloved to memory proves that, above all, it is their desire not to be forgotten than leads them to be catalysts of great change.
