Here’s what’s happening in the world of television for Thursday, March 29. All times are Eastern.
Arrow (The CW, 9 p.m.): There hasn’t been nearly enough for Willa Holland’s Thea to do this season, so perhaps that will finally be rectified with this new story. Nyssa Al Ghul returns to Star City with a warning for her: A group of renegade League Of Assassins are dead set on attacking her. They’re going after a mysterious box Malcolm left behind. Perhaps it contains a chance for Thea to get a good storyline? Or maybe that long-stymied happy ending? Either way, Allison Shoemaker will be there with a report for you.
Siren (Freeform, 8 p.m.): Allow me to assure you: This show about killer mermaids is bonkers. Whether it’s your particular flavor of bonkers is a question whose answer will remain between you and your god—at least until you give it a try (tonight’s premiere features the first two episodes back to back), return here, and say, “Dear god, this ridiculousness is absolutely great/awful/etc.” I look forward to your responses.