New spoilers for "The Flash" feature a returning villain from season 1 as Britne Oldford is reprising her role as Shawna Baez a.k.a. Peek-a-Boo in the Season 4 premiere of the CW Network series.

Who is Peek-a-Boo?

Peek-a-Boo made her debut in "The Flash" Season 1 episode "Crazy for You." After being exposed to dark matter energy from S.T.A.R. Labs particle accelerator, she became a metahuman and has the ability to teleport everywhere within her line of sight. Shawna and her boyfriend, Clay Parker attempted to rob an armored truck but were eventually captured by The Flash and placed in the team's pipeline prison.

She was freed along with Weather Wizard, The Mist, Deathbolt, and Leonard Snart/Captain Cold and Lisa Snart/Golden Glider in episode 22 "Rogue Air" within the same season.

According to Entertainment Weekly, Peek-a-Boo will be the first villain that Team Flash will face during "The Flash" season 4 premiere "The Flash Rebirth," but her motives in the episode is still unknown. Oldford is known for her various TV roles as Cadie Campbell in "Skins," Alma Walker in "American Horror Stories" and Regan in "Hunters."

Is Wally West replacing Barry Allen as Central City's hero?

Perhaps one of the biggest questions in "The Flash" Season 4 will be who is the main "Flash" of Central City? With Barry Allen gone, this leaves Wally West to protect it along with the rest of Team Flash.

Barry willingly went to the Speed Force after he defeated Savitar to answer for his past mistakes in creating "Flashpoint." He left everyone including his fiancee, Iris West.

In the comics, Barry Allen sacrificed his life to save the multiverse from the Anti-Monitor during the "Crisis of Infinite Earths" story. Wally West, who was Kid Flash at the time, took on the mantle of The Flash after Barry's demise and eventually surpassed his mentor, becoming the "fastest" member of The Flash family.

However, Keiynan Lonsdale told Newsweek that Kid Flash will not be taking over Barry's place, stating that Wally still has much to learn before he can properly take Barry Allen's place as Central City's main protector. He has yet to see how his character will head during the first phase of "The Flash" Season 4.

It is unknown what kind of role will Wally has in the course of "The Flash" Season 4, but the first episode will likely give the young speedster a chance for the spotlight in the series before Barry's actual return from the Speed Force.

"The Flash" Season 4 will premiere on Tuesday, Oct. 10 8 PM on The CW Network.