Mallory Jansen LMD
Mallory Jansen will play Aida “Marvel’s Agents of S.H.I.E.L.D.” Season 4. She is pictured at a Marie Claire party on April 11, 2016 in Los Angeles. Getty Images

“Marvel’s Agents of S.H.I.E.L.D.” is growing in Season 4. The ABC drama will add several new characters when it returns, but it still isn’t clear if any of these newbies are friends or foes. From professional competitors to new superheroes, there are plenty of new faces to meet.

Aida: Audiences almost met her in the Season 3 finale. Aida will be played by Mallory Jansen, according to TVLine, and she is Dr. Radcliffe’s (John Hannah) Life-Model Decoy (LMD). Executive producer Jed Whedon said that Aida is supposed to be helpful — but she might be more of a problem.

“[Radcliffe] thinks he’s solving a problem right now, and he says, ‘Fitz and Simmons had friends die, maybe they didn’t have to.’ I think he thinks there might be a solution to some of these problems they’ve faced. Whether or not he’s creating a solution or a new problem, we’ll have to wait [and] see,” Whedon teased to IGN in May.

Director: Jason O’Mara is playing the new guy in Coulson’s old job. The man, who was a character in the comics, becomes director when S.H.I.E.L.D. goes public again. Since Phil Coulson (Clark Gregg) is still believed to be dead, he can’t remain in the position. He will struggle with losing power, and it doesn’t seem like the Coulson’s best agents will love him either.

Ghost Rider: Robbie Reyes (Gabriel Luna) is going to meet the agents in “Agents of S.H.I.E.L.D.” Season 4, but it isn’t clear what his relationship with the team will be. The mechanic has a developmentally disabled little brother, Gabe, that he takes care of when he’s not being possessed by Ghost Rider. However, it’s the possession part that’ll likely have the team questioning if they can trust him.

“The Ghost Rider is a completely separate thing from Robbie,” Luna told the Hollywood Reporter. “It’s something that always inhabits his body and something that he always has to fight. It’s an evil thing.”

A Politician: Another suspiciously nameless character will be played by Parminder Nagra. She is taking on the role of “a powerful political figure who is outspoken in her distrust of Inhumans and the threat they pose to society,” Marvel reports. Expect her to butt heads with Coulson and the pro-Inhuman agents.

Meet the new characters when “Marvel’s Agents of S.H.I.E.L.D.” Season 4 premieres on Tuesday, Sept. 21, at 10 p.m. EDT on ABC.