Albeit brief, the trailer for April 16's episode of Arrow -- the Flash tie-in titled "The Man Under the Hood" -- seemingly gave viewers their first looks at a pair of well-known DC Comics characters who will be series regulars on The Flash.

The trailer, just released online, gave a blink-and-you'll-miss-it look at characters who seem to be Danielle Panabaker as S.T.A.R. Labs's Caitlin Snow (best known in the comics as Killer Frost) and Carlos Valdes's Cisco Ramon, better known as the Justice League member Vibe. While the the quick cuts make it hard to be positive, the fact that the female character's computer features the S.T.A.R. Labs logo suggests we're reading it right.

You can see "Vibe" above and "Killer Frost" below. We'll work to find a better-quality image when it's made available online. We've also got a feeler out to The CW to confirm that these are, in fact, the actors in question.

With his life as both Oliver Queen and the Arrow falling apart at the seams and Slade Wilson recruiting an army of convicts to take over Starling City by force, it seems Oliver heads to Central City to recruit the help of S.T.A.R. Labs's brilliant scientific minds in helping him to overcome the effects of the Mirakuru that have made Slade functionally immortal.

In the “The Man Under the Hood,” Oliver (Stephen Amell), Canary (Caity Lotz), Diggle (David Ramsey) and Felicity (Emily Bett Rickards) return to the lair and find Slade (Manu Bennett) waiting for them. An epic battle breaks out and one member of Team Arrow is sent to the hospital. Thea (Willa Holland) hits her breaking point, but just as Oliver is about to reach her, Slade intervenes and Oliver is faced with a choice – his battle with Slade or his family. Meanwhile, Laurel (Katie Cassidy) struggles with the realization that Oliver is the Arrow.

“The Man Under the Hood” episode of Arrow is directed by Jesse Warren and written by Greg Berlanti & Geoff Johns and teleplay by Andrew Kreisberg & Keto Shimizu. “The Man Under the Hood” is scheduled to air on Wednesday, April 16, 2014 at 8 PM ET on The CW.