Jemma Simmons' growing darkness will soon come to a head on Agents of SHIELD.

No one knows the truth behind Bakshi's death, but Simmons' dark side will come to the team's attention before the credits role on the season 2 finale. Someone - whether it be Fitz or Coulson - will soon notice that the biochem genius is not quite the peppy, trusting Simmons that stepped onto the Bus last year.

"Yes," executive producer Maurissa Tancharoen said, according to Zap2It, when asked if Simmons' murderous side will become another agent's concern, adding that the science wonder twin "feels like she has to [take this stance]. It's a reaction to everything she's been through. It's a reaction to Trip's death."

However, the caring Simmons of days past will also crop up from time to time.

"I think you'll see a little bit more the side of Simmons that you saw when you first met her," executive producer Jed Whedon explained, according to Zap2It. "But I also think that, yes, she's taking a hard line."

New promo art (see here) indicates that while Coulson and Co. deal with the Inhumans threat during "SOS," FitzSimmons will have their hands full with Marvel's own Jekyll and Hyde, one Cal Johnson.

Will Cal's combustible nature draw parallels to Skye's recent behavior? Find out when Agents of SHIELD airs Tuesdays at 9 p.m. ET on ABC. Click the video below to see a preview for the series' next episode.

Tags: Marvel's Agents of S.H.I.E.L.D. television Marvel ABC