This episode is just amazing. Every character has been cast perfectly and acted beautifully. Reactions of Doctor and Shakespeare are priceless in their exchanges. The best of the lot is Doctor's reaction at learning about the origin of the Sonnet 18. Had to watch the episode many times, enjoyed and laughed out loud every time. Dean Lennox Kelly totally nailed portrayal of the Bard, at least in the comic sense it is supposed to be, and Christina Cole has to be the most beautiful witch ever. I got into Doctor Who for the futuristic storyline, but the episodes I loved most were when Doctor goes to past and meets historical figures - The Unquiet Dead and Tooth and Claw to name a couple. Still going through only third series, so a better episode might yet to come.