It’s back for another season of artisanal humor, with 10 new episodes. Carrie Brownstein and Fred Armisen (above) have come up with a wonderfully droll and affectionate series about a city and its unique culture. I love the show, despite its hit-or-miss quality. Some of the sketches — the “cacao” and the Aimee Mann bits — are unforgettable. Guests this season will include Roseanne Barr, Rose Byrne, Bill Hader, J Mascis, and Chloe Sevigny as Fred and Carrie’s new roommate.

Merlin 10 p.m., Syfy

And so it came to pass, last season, that Gwen and Arthur were finally married. And so it was, too, that she was no bridezilla, and there was much joy in the castle and thereabouts. But the fifth and final season begins Friday night, with the evil Morgana causing more trouble, and methinks it’s not going to end well. Methinks, as do a whole bunch of writers and filmmakers.

Warped Roadies 11 p.m., Fuse

“Hell on Wheels.”

Unearthing Ancient Secrets 10 p.m., Science Channel

“Joan Rivers: A Piece of Work.”

Ex-Wives of Rock 10:30 p.m., Fuse