“The Flash” has found its Season 4 big bad.

“The 100” alum Neil Sandilands was tapped to play Clifford DeVoe, aka The Thinker, in the upcoming season of the CW series. Sandilands’ casting was announced at the show’s San Diego Comic-Con panel on Saturday.

According to the character’s official description, DeVoe became an extremely intelligent metahuman after he was caught in the particle accelerator explosion. DeVoe is the show’s main villain next season, and being the super genius that he is, he has plans to fix all he sees wrong with humanity.

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In addition to his role as Titus on “The 100,” Sandilands has also appeared on FX’s “The Americans” and SundanceTV’s “Hap and Leonard.”

Besides Sandilands, “The Flash” has also cast Kim Engelbrecht and Danny Trejo for Season 4.

Engelbrecht will play DeVoe’s right hand, The Mechanic. Described as an extremely intelligent engineer, The Mechanic designs devices for DeVoe and support him no matter the consequences. Engelbrecht is best known for her role as Sgt. Noma Banks on Syfy’s apocalyptic supernatural series “Dominion.”

Trejo, meanwhile, will play the role of Breacher, a feared bounty hunter from Earth-19 who happens to be the imposing father of the inter-dimensional bounty hunter, Gypsy (Jessica Camacho). Breacher’s job is to prevent any inter-dimensional traveler from threatening life on his planet — especially his daughter’s. Breacher is expected to clash with Cisco (Carlos Valdes) and the rest of Team Flash because of their connection to Gypsy.

News of Sandilands, Engelbrecht and Trejo’s addition to the cast comes a week after it was revealed that Britne Oldford is reprising her role as metahuman Peek-a-Boo in Season 4 premiere of “The Flash.”

Peek-a-Boo, aka Shawna Baez, last appeared in Season 1, episode 22, where the Reverse-Flash (Tom Cavanagh) freed her and other metahumans from the Pipeline. She nearly killed Caitlin (Danielle Panabaker) for imprisoning her but was knocked out by Iris (Candice Patton) and returned to her cell. She and other metahumans were then sedated and were moved out of S.T.A.R. Labs in a truck. However, Team Flash’s plan to transport the metahumans to another location became a disaster when siblings Leonard (Wentworth Miller) and Lisa Snart (Peyton List) sabotaged the truck. A battle ensued, but Shawna decided to take the opportunity to escape, teleporting away.

“The Flash” Season 4 will premiere on Tuesday, Oct. 10 at 8 p.m. EST on The CW.