Missing the Sunday night appointment television rush of “True Blood?” Well, everyone’s favorite serial killer-killing serial killer (say that ten times fast) is back with an infusion of frightening fun.

This season Dexter faces not only the complexities and sheer exhaustion of fatherhood, but a new nemesis called “The Trinity Killer,” who may turn out to be a father figure to Dexter. But, it’s not just premium channels offering premium television this weekend.

Documentarian Ken Burns delivers a six-part series on PBS called “The National Parks: America’s Best Idea.” Filmed over six years, this series looks at the creation of the National Parks system and the people behind it–John Muir, Teddy Roosevelt, the Civilian Conversation Corps–and it promises to be as vast as Death Valley, as deep the Grand Canyon, and just as breathtaking.

“Dexter” airs at 9 p.m. on Showtime. “The National Parks: America’s Best Idea” begins at 8 p.m. on PBS.  Check your local listings.