In “Hamlet,” the assumption most people make is that Ophelia commits suicide. It makes sense; she kind of goes cuckoo for Cocoa Puffs after Hamlet kills her father (Polonius), which puts a damper on any prospective wedding plans. But what’s odd about Ophelia’s death is that it happens offstage and the person who informs Laertes (Ophelia’s brother) and King Claudius of the event is Queen Gertrude. Now, if Gertrude discovered the body, then it’s logical for her to seek out Ophelia’s brother to let him know. Except Gertrude knows much more about the death than is reasonable. She explains in great detail all the flowers Ophelia adorns herself with before she drowns, Gertrude knows the exact branch Ophelia initially tries to hang herself from, she describes in vivid language what Ophelia looks like in the waters, and can even say with certainty that Ophelia sings songs while she’s drowning. All of this suggests that Gertrude is at the very least present at the time in question, if not the perpetrator behind it.
Gertrude killing Ophelia would also be a perfect thematic fit because it completes the family of murderers—Claudius poisons his brother, Hamlet stabs Polonius, and Gertrude asphyxiates Ophelia. Furthermore, before Ophelia’s death, the two women in “Hamlet” are established as foils to one another. Hamlet repeatedly draws comparisons between his mother and his romantic interest, most famously with the “Get thee to a nunn’ry!” scene. Symbolically, Ophelia is the forgotten innocence and advancement of Denmark as the (assumed) future mother of Hamlet’s children. At one point in her life, Gertrude would have represented the same thing when she was married to Hamlet’s father. For Gertrude to be the murderer means that she is literally and figuratively shattering any sense of purity within the kingdom and within herself.
Believing that Gertrude kills Ophelia also makes the Queen’s actions and lines clearer in meaning. Just before seeing for the first time the extent of Ophelia’s madness, Gertrude comments that “So full of artless jealousy is guilt, / It spills itself in fearing to be split” (4.5.19-20), which means that a guilty conscience makes you foolishly suspicious to the point where you make your guilt obvious for other to see. The next question is: what does Gertrude believe she is guilty of? For one, there’s Hamlet’s presumed madness, which Hamlet himself suggests is caused by Gertrude’s incestuous and hasty remarriage to her brother-in-law. Another reason could be Polonius, who Hamlet killed in Gertrude’s bedchambers because he thought he was Claudius. Thinking of the line as a foreshadowing, though, makes the moment when Gertrude explains how Ophelia died more significant. Essentially, she is trying so hard to convince Laertes and Claudius that the death was a suicide that she is “spilling herself.”
The problem I think most people might have with my theory so far is that it’s merely circumstantial evidence—why would Gertrude want to kill Ophelia? Well, I think the answer might be that Gertrude actually wants to kill herself. As mentioned previously, no matter what Gertrude and Ophelia say or do, it is immediately reflected thematically onto the other. Gertrude holds a lot of guilt about her remarriage, because as the Queen, she is not upholding the virtues a queen is supposed to represent. Ophelia, as the future monarch, should also represent the same virtues. There’s even a line where Gertrude tells Ophelia: “I hope your virtues/ Will bring [Hamlet] to his wonted way again” (3.1.39-40), which is the Queen’s way of saying that Hamlet’s madness is directly related to Ophelia’s virtuous nature. But as events play out, Hamlet doesn’t get better; he gets worse and reaches the breaking point with the murder of Polonius. However, since Hamlet’s insanity can also be tied to Gertrude’s remarriage, Gertrude holds just as much guilt as Ophelia.
Basically, my argument is that Gertrude uses Ophelia as a scapegoat for her own guilt. I believe that Gertrude tries to rationalize Hamlet’s insanity and the downfall of Denmark as a blemish on Ophelia’s own character. In killing Ophelia, Gertrude is trying to restore a sense of order to the world, which ultimately fails and leads to Gertrude’s own death at the end of the play.