RALPH:  Claudius and Hamlet are both trying to figure out exactly how much the other one knows. Hamlet has his plan:  stage a play re-enacting the details of his father's murder and watch Claudius' response.

SARAH:  Earlier, Claudius used Rosencrantz and Guildenstern to try to discover the extent of Hamlet's knowledge - without much success. In this scene we see if he has better luck using Ophelia.