Serial killer drama is most-watched series on Showtime

Showtime is set to announce a sixth-season pickup for “Dexter.”

Michael C. Hall serial killer drama has been the pay cabler’s most popular show in recent years. Last Sunday’s episode was the second most watched in series history as 2.54 million viewers checked in for the 9 p.m. telecast. Last season’s finale drew the show’s biggest-ever aud, with 2.57 million viewers.

All key cast members are signed through the sixth season, which will encompass 12 episodes. But if the show runs a seventh season, Showtime will face higher costs as cast members would have to sign new contracts.

“Dexter” is exec produced by Hall, Chip Johannessen, John Goldwyn, Sara Colleton, Manny Coto and Scott Buck.

Follow @Variety on Twitter for breaking news, reviews and more