The play within a play has long been understood as Hamlet's attempt to catch the conscience of the King. But is that all it is? Perhaps there's more to the "Murder of Gonzago" than either Hamlet or even Shakespeare, himself, intended? While the narrative of the Player King and Player Queen clearly works to tap into the private guilt of King Claudius, it also does much to reveal the hidden psychology of Gertrude, a woman whose motives and psychological underpinnings are often concealed to the audience. The purpose of this article is to use the play within a play as a meta-text through which the reader can learn to decode, first, who Gertrude was, both as a wife and a person, prior to Hamlet Sr.'s death, and, second, offer an explanation for why she remarries so quickly in the wake of her first husband's murder. In this sense, though Hamlet designs the play within a play to gain ocular proof of Claudius' crime, he may unconsciously also do so to catch the conscience of his mother, and thereby better understand himself. The play "within" a play within a play's the thing.