For a guy with a reputation as a hothead, Laertes comes around to this conclusion rather quickly. I’m actually curious about what changes Laertes’ mind about Claudius. It happens so fast. He’s getting twinges of conscience and then once he kills Hamlet, it’s like he starts to see more clearly. It could be the clarifying process of death, I suppose. In seeing his end so soon ahead of him, perhaps it all falls into place. Or is there something that Claudius does or does not do that makes it obvious to Laertes? Letting Gertrude die is one thing but Laertes is as aware as the king of that fact, as it is happening, and he is still ready to do the king’s bidding. So I don’t think it’s Gertrude’s death that shifts his opinion of the king. I wonder if there’s a way in the fight that the king could be seen as responsible for Laertes’ death as well. Like – once Laertes has struck Hamlet and it should be over, Claudius lets it continue and while Laertes is looking to the king for support, Hamlet seizes the moment to strike back. That is, is there a way to show the moment when the king loses Laertes’ loyalty. The king is likely to be just as happy to have Laertes killed as the rest. Laertes is, after all, the key witness to this plot that has killed the Queen and Prince of Denmark. It would be convenient for Claudius if he were also dead after this fight.
It could, of course, just be Laertes’ conscience kicking in at the end of his life that has him give up the king but…there could be more.