By James Hibberd
Updated April 11, 2011 at 11:52 PM EDT

Two big new cable dramas had two different stories to tell their second week on the air.

Ratings for AMC’s The Killing held up for its the grim, rainy mystery’s second episode, delivering 2.6 million viewers Sunday night during its hour — that’s compared to last week’s 2.7 million for a two-hour episode debut.

But viewership for Starz’ Camelot fell, with Friday’s episode dropping to 850,000 viewers from the previous week’s double-length episode. That’s down 23% from the premiere’s record-tying series opener for the network, yet is still considered a good number for Starz. As for Showtime’s The Borgias, those numbers will be out tomorrow…