Agent Fitz (Iain De Caestecker) will not rest until he finds Agent Simmons (Elizabeth Henstridge) in the upcoming season of the ABC series "Agents of S.H.I.E.L.D."

Comicbook Resources reports that Fitz will even enlist the aid of an Asgardian to unlock the secrets of the ancient monolith, the Kree stone, which swallowed his partner. According to speculations, the person who will help the agent is none other than the mighty Thor. Sources posit that the hero and his Lady Sif will be turning up in the second episode of the series titled "Purpose in the Machine."

With the information he can get from the Asgardian, Fitz can be much closer to the reunion he has been dreaming of with Simmons. While the rest of the team, including Phil Coulson (Clark Gregg) has given up on locating her, Fitz is reportedly the only one steadfast enough to pursue the investigation. He will even go on a solo mission to find his partner, even though the danger is very real.

In a teaser released by ABC for the premiere episode, Fitz will be seen going to extreme lengths to find Simmons. He will be alone in this undertaking, however, as the entire team will come face-to-face with another organization bent on rounding up the Inhumans. Coulson and the gang must race against time to find the powered people first before the enemy manages to locate all of them.

As for Fitz, Simmons' disappearance will be only thing that occupies his mind. In an interview with Zap2it, Henstridge talked about her character's disappearance and Fitz's determination to get her back.

"What happened was so crazy and there was no trace of her, that what do you do? I think that the whole team has tried and nothing has worked, so at some point you have to go, 'She's gone, we have to move on.' But Fitz refuses to do that."

Marvel's "Agents of S.H.I.E.L.D." season 3 will premiere on Tuesday, Sept. 29, at 9 p.m. EST on ABC.