THE CHANGE: He's the cold and calculating patriarch of the richest, cruelest family in Westeros. She's the wild-child daughter of a fallen hero, on the run from forces sworn to destroy her. Together they're dynamite! In the books, Arya spends Lord Tywin's time in Harrenhal as a peon who only catches the occasional glimpse of House Lannister's top dog; the show's incognito-cupbearer plotline is grafted in from another section of the book.
THE VERDICT: Maisie Williams plus Charles Dance equals great TV. It's pretty much just that simple. Kudos to the show for finding a way to have one of its best child actors (and it's got more good ones than some entire networks) and its most commanding actor/character combo (Dance looks nothing like Tywin in the books but it's now hard to imagine him any other way) go head-to-head on the regular. Arya's less-than-effective cat-and-mouse stuff with Littlefinger and Lorch is a small price to pay.