‘The Flash’ spoilers: When will Katie Cassidy guest-star as Laurel?

If there is a major death coming up on “Arrow” when the show returns April 15, we can offer you at least one reassurance right now: It is officially not going to be Captain Quentin Lance. The man is at the center of the Oliver Queen manhunt, but who knows? Maybe he is going to calm down when that episode airs.

Based on some of the first details that we have for the April 21 episode of “The Flash” entitled “Who Is Harrison Wells,” Lance seems to be in a better mood … or at least he is willing to help try to figure out some of Harrison’s biggest secrets. This episode is going to feature both Paul Blacktorne and his onscreen daughter Katie Cassidy as guest-stars; you’ve seen that scene with Cisco and Laurel a few times in promos already, and it will be taking place within this hour. Take a look at the just-released synopsis for more, including the arrival of new villain Hannibal Bates:

“Joe (Jesse L. Martin) and Cisco (Carlos Valdes) head to Starling City to continue their investigation of Dr. Wells (Tom Cavanagh). While in town, the duo enlists the help of Captain Lance (guest star Paul Blackthorne), and Cisco meets the Black Canary (guest star Katie Cassidy), who asks him for a favor. Meanwhile, back in Central City, Barry (Grant Gustin) races to catch a meta-human named Hannibal Bates (guest star Martin Novotny) who can transform himself into every person he touches – which includes Eddie (Rick Cosnett), Iris (Candice Patton), Caitlin (Danielle Panabaker) and even The Flash.”

Given that this episode is fairly close to the end of the season, we’re admittedly somewhat surprised that there is another meta-human entering the fray. Remember here that you also still have Captain Cold and Heat Wave on the loose; not only that, but Gorilla Grodd is off somewhere on a rampage. Last we saw, he was busy clobbering General Eiling after Dr. Wells suggested so.

Just in case you’re not excited enough after hearing this synopsis, head over here to watch a lengthy preview for what lies ahead this season! Also, sign up to score some other TV news in a flash via our CarterMatt Newsletter. (Photo: The CW.)