"Da Vinci's Demons": Just as "Spartacus" breathes its last, Starz may have a new spring/summer hit here. With a creator versed in both big box office ("The Dark Knight") and gamer spectacle ("Call of Duty: Black Ops), the show puts one of history's most famous and revered artists into an action hero-like context, complete with secret societies and a mystical text. Oh, and this being Starz, plenty of sex 'n violence.
It's great fun, romping through Renaissance Florence and Tuscany on the tunictails of Leonardo (Tom Riley) as he develops his talent for portraiture and engineering. History majors, art or otherwise, probably shouldn't waste time taking notes, although younger viewers may find themselves moved to Google Da Vinci for the first time, and that can't be a bad thing. But for those secretly longing for "Assassin's Creed: The TV Show," this is your chance. Just remember, you must go where one story takes you, but then there's no danger of being killed off, either. Starz, Friday, 10 p.m.
"Doctor Who": Jenna-Louise Coleman is settling in nicely as Clara, the Doctor's new, and highly mysterious, companion on "Doctor Who" and she is certainly being tested by extremes. Last week took her to a galaxy far, far away to do battle with a hungry sun; this week finds her underneath the sea on a submarine doing battle with ice warriors. The Doctor doesn't often find himself under water, and as this episode is from the reliably unpredictable Mark Gatiss (who should be off somewhere filming the next installment of "Sherlock" if he knows what's good for him), it would be a mistake to miss it. BBCAmerica, Saturday, 8 p.m.