|First Appearance||Everybody Has Their Reasons|
|Last Appearance||Stalag 14th Virginia|
|Allegiance||14th Virginia (original)|
|Age||Mid to late 40's|
|Occupation||U.S. Military Captain|
|Family||Burt - Former Boyfriend|
|Cause of Death||Killed by Skitters. (original)|
Stabbed by Daniel Weaver. (clone)
|Katie stabbed by Daniel Weaver.|
|“||I'm sorry. I wasn't perfect. She was just an experiment. But she still feels. She remembers... the memories... of loving you.||”|
— Katie-clone to Weaver while dying.
Katie Marshall was a survivor of the invasion and a soldier of the U.S. military. An old colleague and flame of Colonel Daniel Weaver, she commanded the 14th Virginia and commanded a functional military base in Norfolk after the initial invasion of Earth by the space-fearing Espheni.
Three years after the invasion, Marshall was killed by the Espheni in an ambush and a clone replaced her as commander of the 14th Virginia. The Overlords used their new puppet to launch a witch hunt against all human "collaborators", fighters who had alledgedly followed the Espheni but who were in fact trying to oppose them. Several "traitors" were rounded up, fast-tracked through trials and executed.
Six weeks after the clone replaced Marshall, the 2nd Massachusetts Regiment arrived at her base. Determined to ally with the 14th Virginia for a march against an Espheni base in Washington D.C., Marshall nevertheless prosecuted the 2nd Mass's second-in-command, Tom Mason, as a traitor, officially due to his sketchy history with Espheni technology but unofficially to rid the Overlords of one of their greatest human enemies. However, her actions led the 14th Virginia to mutiny against her and join the 2nd Mass. As she attempted to kill Tom Mason, Marshall's clone was killed by Weaver and her duplicity was exposed.
As a soldier in the military, Marshall has just arrived into Fallujah, and Colonel Weaver got stuck with her while they were pinned down by insurgents. They developed a close relationship as a result. Katie and a soldier Burt began to date, however he couldn't continue with the relationship as he saw how Daniel Weaver took care and looked at her.
Katie knows that Weaver's strength was loyalty, and also his weakness. That he stuck it out in a marriage he knew was doomed, and covered for the brigadier general when he was drunk. Weaver also covered for Marshall, but knows she should have been reprimanded, not have had the heat taken off her, and that's the moment she knew she loved him.
Invasion of EarthEdit
During the invasion, Marshall saved Demarcus Wolf's life. Marshall reopened a naval base in Norfolk, where she brought in navy and military soldiers to fight the human collaborators and the aliens, calling themselves the 14th Virginia.
After a close call with skitters, Marshall was attacked and scratched on her neck by a skitter. After that, Wolf states that it's like she's got ice running through her veins now, and she is worrying too much about the collaborators than the aliens.Daniel Weaver. Marshall gives Weaver and Tom Mason a guide of the naval base, giving the history. Marshall goes over Tom's plans about attacking DC, and Marshall learns that the 2nd Mass have been fighting with the Volm. Weaver decides to have breakfast with Marshall, as they revisit old times before the invasion. Katie Marshall approaches Tom asking why he is giving orders to her men. Tom wants to know why they are not contacting other militias and that they are all supposed to be on the same side, however she seems dead set on focusing on human collaborators and not major offensives. After soldiers torture Tom's son, Ben, Tom goes to Lt. Shelton and threatens him, telling him that he is also a collaborator, having eye worms and being on an aliens ship. Marshall places every 2nd Mass member under arrest.
At the court martial, Marshall goes through each and every case in which Tom was captured and found his way back without explanation and she just can't believe any of its true. When Tom begins to berate her about the entire thing being a farce, she stares out into nothing and her wound on her neck begins to bleed again. She closes the file on Tom, Ben and Hal and declares them traitors, charging them with treason for which the sentence is death.Marshall meets with an Overlord who is killed by Weaver. She later stops an attempt by the Masons to escape, though Tom Mason manages to get away. Seeing that Marshall has gone too far and is turning their hunt for collaborators into a witch hunt, Lieutenant Shelton tries to relieve her of command in favor of Colonel Weaver, but is killed from behind by Zak Kagel who is loyal to Marshall. The next morning Marshall goes through with the executions, allowing Anne Mason some final words. However, her firing squad hesitates as they realize what she's doing is wrong and Tom arrives with reinforcements from the 2nd Mass, including Cochise. All but Kagel, who is killed by Isabella, surrender without a fight and Tom uses Cochise as an example of how the Volm aren't their enemies and they need to work together. Marshall attempts to shoot Tom, but is stabbed in the side by Weaver. Everyone realizes she is not the original Katie Marshall when they see that her blood is black and as she dies, she explains how she is an Espheni clone and experiment, but wasn't perfect as she still retained human emotions and the real Katie died in the ambush six weeks back. With the Marshall clone's death, the 14th Virginia joins with the 2nd Mass, all now falling under Weaver's command.
|Season 5 appearances|
|Find Your Warrior||Hunger Pains||Hatchlings||Pope Breaks Bad||Non-Essential Personnel|
|Respite||Everybody Has Their Reasons||Stalag 14th Virginia||Reunion||Reborn|