 Due to the Halloween concept of the episode , the cast members of The Office were allowed to wear costumes rather than their " usual , realistically plain suits " . B.J. Novak , writer for the series as well as actor , called the experience " fun " . The episode features the last on @-@ screen appearance of the background character Devon until the series finale . The episode earned a Nielsen rating of 4 @.@ 1 in the 18 – 49 demographic and was viewed by 8 million viewers . 
