Agents of SHIELD will team up with Lucy Lawless in season 2, and the Zena star will make her debut in the fall premiere.

FitzSimmons 'Complicated Feelings' Arise Following Fitz's InjuryOn 'Agents Of SHIELD'

Viewers can check out Lawless' Agent Isabelle Hartley in the first official still from the season opener. Billed as a seasoned SHIELD operative that is presumably free of HYDRA connections, Hartley is expected to help Director Phil Coulson (Clark Gregg) rebuild his crippled agency.

Unfortunately, fans cannot assume that Hartley will be as loyal as one may hope. Considering Coulson's team had a HYDRA mole in it from day one, no character is completely above suspicion.

Skye's Father Cast For 'Agents Of SHIELD', Kyle MacLachlan Takes Monstrous Role

"We think we can keep that 'Trust no one alive' [feel]," teased co-creator Jed Whedon, according to IGN.

"That's one of the things we're going to be exploring in [season 2]," added executive producer Jeffrey Bell. "Who's out there? Who went to Hydra? Who didn't? Who can we trust?"

In addition to Hartley, Coulson will receive aid from Nick Blood's Lance Hunter, Henry Simmons' Alphonso 'Mack' Mackenzie, and the Mockingbird.

Find out more when Agents of SHIELD returns to ABC on Sept. 23 at 9 p.m. ET. Click the video below to see a preview for the series' ltest episode, "Beginning of the End."

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