The STAR Labs braintrust better have their thinking caps handy. “The Flash” is rounding up heroes and villains alike for Season 4 and, based on the latest casting call, the newbies will give Barry Allen a run for his money.

Not literally, of course. For the first time since its inception, the “Arrow” spinoff won’t front a speedster as the season’s big bad. Find out who will send Central City reeling – and who will aid Team Flash – thanks to the latest teasers from the Hashtag Show.

The who’s who of season 4

Once Barry (Grant Gustin) manages to pick the lock on his Speed Force prison, he’ll find the streets of Central City just as dangerous as ever.

Kid Flash (Keiynan Lonsdale) and Vibe (Carlos Valdes) will hold down the fort under the direction of Iris (Candice Patton) and Joe (Jesse L. Martin), but no amount of heroic metas can truly stem the flow of their villainous counterparts.

A victim of the particle accelerator explosion, Clifford DeVoe (aka The Thinker) suddenly found himself endowed with a prodigious intellect, which he plans to use as a balm for society’s flaws. It’s easy to imagine how quickly those “good intentions” might unleash a wave of chaos. After all, it’s a trope we’ve seen play out across the DC and Marvel brand time and time again.

Every good villain needs a partner in crime, and DeVoe will find his in The Mechanic. A female aged 30-40, this engineer come equipped with skills on par with Cisco’s and a desire to stand by The Thinker no matter the consequences.

It’s a dangerous combination, to be sure.

Meanwhile, Ralph Dibny (aka Elongated Man) will provide a little comic relief. We usually turn to Cisco when we need a laugh, but his life grows darker with each passing season. Possessed with the wit and timing of Chris Pratt or Ryan Reynolds, Dibny will find it easier to morph his body than to change his ways.

While it’s unknown if he will join the CCPD in an effort to exercise his canonical sleuthing skills, we can tell you he has the potential to survive into season 5.

Next time on ‘The Flash’

Following the events of “Finish Line,” Barry willingly replaced Savitar in a prison of his own creation. Locked into his own personal hell, the Scarlett Speedster will spend six months away from Iris, waiting for Cisco and co.

to secure his release. Viewers, however, will merely have to wait one episode. Titled “The Flash Reborn,” the Oct. 10 premiere promises a heartfelt reunion.

Even as Wally and Cisco deal with a mysterious samurai, old foes will drop back into the picture. Peek-a-Boo (Britne Oldford) will return, according to Entertainment Weekly, but the exact nature of her Iron Heights escape/release remains under wraps. Details regarding the future of Killer Frost/Caitlin Snow (Danielle Panabaker) are slim to none.

Find out more when “The Flash” airs Tuesdays at 8 p.m. ET on The CW.

Don't miss our page on Facebook!