"Downton Abbey" creator Julian Fellowes will write a prequel to his hit show that will explore the beginnings of the relationship between key characters Earl (Robert) and Countess (Cora) of Grantham, set for broadcast after the last episode of the original airs. "The spin-off drama will cast a pair of younger actors in the roles," which are currently played by Hugh Bonneville and Elizabeth McGovern, writes Stuart Kemp. Key question for "Abbey" fans: Will the prequel include the Dowager Countess, played so memorably now by Maggie Smith, who just won an Emmy for her role?