The Boardwalk Empire actress will appear in the show's third season finale as a rookie FBI agent.
"We try and expand our storytelling week to week to a way that we are able to tell... deeper stories about our main characters," Wyman told Entertainment Weekly. "Many of the guest stars that come on are there to do one main thing, and that's to reflect back on our main characters."
He continued: "[Through the guest characters, we] learn more about them and sort of uncover more aspects of their personality and deepen them for the viewer. [Emily's] character will definitely be there to do that."
Wyman also admitted that the role has the potential to recur in the show's recently-confirmed fourth run.
"We always protect ourselves by saying that, because you never know," he explained. "When we used Seth Gabel [as Lincoln Lee], for instance, he turned out to be so great. We always like to just know that we're covered, should it go great."
Co-producer Jeff Pinkner previously claimed that the season finale, which is expected to air on May 6, will "unfurl in a very unexpected way for the characters and the audience".
Fringe will return to Fox on April 15.
> The past and future of Fringe