Why Jamie Killian From Chicago Fire Looks So Familiar

"Chicago Fire" has no shortage of characters willing to put their lives and health on the line to protect the Windy City. Not only does the series follow their exploits as they battle raging fires and help the sick, but it also delves into the characters' personal lives. It helps to show that there are real people on the other side of those uniforms, and they have lives as rich and complex as anyone else. 

Nowhere is that more apparent than long-standing character Lieutenant Kelly Severide (Taylor Kinney). The charismatic firefighter has long been a member of Rescue Squad 3, but when he isn't battling blazes, he can be quite the ladies' man, as evidenced by a Season 4 arc where he starts going out with lawyer Jamie Killian (Rachel Nichols). She may not have been on the series for very long, but she certainly made an impact. After all, actress Rachel Nichols has been incredibly busy over the last few years with a myriad of roles in other projects. Here's where else you may have seen the short-lived "Chicago Fire" actress before.

You'd be forgiven if you didn't realize the "Chicago Fire" actress starred in 2009's "Star Trek." Not only does she sport red hair as opposed to her usual blonde locks, but her skin is also green. 

That's right; Rachel Nichols played James T. Kirk's (Chris Pine) one-time fling Gaila in the science-fiction film. The two share a sexy rendezvous until Uhura (Zoe Saldana) walks into the room. Kirk tries to hide for a period of time, but he's no match for Uhura's expert cognizance, and it doesn't precisely bolster his reputation in her mind. 

It was a small but memorable role, and it required quite the dedication for the young actress. She looked back on the part for an interview with StarTrek.com: "It was a lengthy process to get me that green, especially for the sexy bedroom scene with Kirk and Uhura. I think hair and makeup was five or six hours, and then you're kind of sticky all day. Then, when Kirk and I would kiss, we'd pull away and Chris Pine's face would be green and my makeup would have wiped off on his face."

2009 was a very good year for Rachel Nichols. On top of starring in "Star Trek," she also appeared in a much larger capacity for "G.I. Joe: The Rise of Cobra." Nichols played Scarlett in the film who functions as the organization's intelligence expert. And since she filmed "Star Trek" before "The Rise of Cobra," she continued being a redhead (via Morning Sentinel).

Much like her preparation of turning green for "Star Trek," the actress had to get ready for something she had never done before prior to this film, but it required a lot more stamina than sitting in a chair for several hours getting makeup applied. As she told Female.com, "I added about 15 pounds of muscle to do the role ... And then about six weeks before the fight scene, Sienna [Miller] and I started training five days a week, a couple hours a day, with mixed martial arts."

Scarlett fighting The Baroness is one of the most memorable moments from the entire film. Of course, the two actresses involved likely remember it for all of the wrong reasons as Miller told MTV, "We both got hurt. I'm clumsy, so I slipped on a rubber bullet at one point and sprained my wrist quite badly. [Nichols] ran into a flame and got burned." It looks like both of them ended up suffering for their art.

In "Titans" Season 1, Trigon may be the big bad, but few characters on the series have managed to be as deceptive as Angela Azarath, played by Rachel Nichols. She gets herself thrown into an asylum, where she ends up reuniting with her biological daughter, Rachel Roth (Teagan Croft). The happy family reunion soon turns sinister when it's uncovered that Angela only wanted to get Rachel back in her life so that she could re-summon the entity known as Trigon (Seamus Dever).

So how is Angela rewarded for being a faithful servant to Trigon? Why he snaps her neck the second he gets a chance, of course. It was a fitting end for the malicious character, but Nichols's career hasn't suffered in the slightest since her time on "Titans." She's continued starring in a number of television series, among them "The Man in the High Castle" and "A Million Little Things."