ABC President Paul Lee announced at the network's TCA Winter Tour panel today that Thor: The Dark World star Jaimie Alexander will reprise her role as Lady Sif in Marvel's Agents of S.H.I.E.L.D.'s 15th episode.

The character comes to Earth with a "very specific mission" in the currently untitled episode, which doesn't have an air date locked in as of yet. The character is said to have an "integral role" in the episode's story, unlike previous cameos from the Marvel cinematic universe such as Samuel L. Jackson's Nick Fury and Cobie Smulders' Agent Maria Hill.

Paul Lee also teased at the panel that the mysterious identity of The Clairvoyant will be revealed at some point during the show's final nine episodes, and that the producers have a "very cool plan" for the second half of Season 1. Despite a significant drop in the ratings, Paul Lee said he feels "very good" about the show, from a creative standpoint.

Marvel's Agents of S.H.I.E.L.D. is currently on hiatus until February 4, when it returns with "T.R.A.C.K.S.", an episode which we reported earlier this week will feature Marvel legend Stan Lee in a guest-starring role.