Denise Christopher is a senior Homeland Security field agent assigned to oversee the time machine recovery mission.
After Lucy Preston is brought to Mason Industries by Agent Kondo, Agent Denise Christopher greets both her and Wyatt Logan. She compliments Lucy about her education, informs her that she's read all of the books written by her mother, Carolyn Preston, and expresses sorrow of her mother's illness. She alludes to Wyatt's extensive military reputation. Connor Mason and Agent Christopher brief Wyatt and Lucy on the existence of time travel and of Garcia Flynn, the time travelling terrorist. Christopher tells Lucy the date and location they need to go to to stop Flynn. Lucy is able to recall that the Hindenburg disaster happens there and then. Lucy and Wyatt are assigned with the mission to take out Garcia Flynn to prevent him from changing history. Lucy refuses to cooperate but Agent Christopher convinces her that she's vital to the mission. Lucy complains to Agent Kondo and Christopher that the disguises they have are not time appropriate, but they are sent back in time regardless.
When Lucy, Wyatt, and Rufus Carlin return, they explain that they were the Anarchist Black Cross and how the timeline was changed. Lucy explains to Mason and Agent Christopher her theory that Flynn is trying to go back in time to destroy America.
1865 - Episode 2: "The Assassination of Abraham Lincoln" Edit
When Lucy, Rufus, and Wyatt are called about by Mason Industries to stop Flynn after he again uses the Mothership to go back in time to change the course of history, Lucy is horrified to find that her sister, Amy Preston, has been erased from time. Christopher tells Lucy that they do not have time to bring Amy back into existence because Flynn is still on the prowl trying to change history. Christopher tells the time team that Flynn has gone back to April 14, 1865. Lucy knows that this is the night of the assassination of Abraham Lincoln, and realizes the severity of the situation.
When the crew returns from 1865, Agent Christopher calls for a medic for Wyatt, because he was shot by Flynn on the mission. The changes to the timeline are once again explained to Lucy, Wyatt, and Rufus by Christopher and Mason. The changes to the timeline make Lucy distraught, but to Agent Christopher, it's close enough, considering the country was not destroyed.
1962 - Episode 3: "Atomic City" Edit
Jiya figures out how to find out not only when Flynn goes back in time, but where he goes. It isn't entirely precise however, it shows where they could be within a fifty mile radius. The time team is able to extrapolate from this data that Flynn traveled to Nevada on September 21, 1962.
When Lucy, Wyatt, and Rufus return from their mission, they tell Agent Christopher the details. History remained relatively the same, but Garcia Flynn was not killed and he obtained a nuclear bomb's core. Christopher is also informed of a not entirely clear partnership between Flynn and Anthony Bruhl. Agent Christopher informs the team they no longer need to save Anthony, but instead need to kill him to leave Flynn without a pilot. Wyatt lies to Christopher, saying he never had an opportunity to shoot Anthony to cover for Rufus who saved Anthony during the mission.
1944 - Episode 4: "Party at Castle Varlar" Edit
Using Jiya's new location detection, Mason Industries raids Flynn's base in 2016. Flynn and Anthony escape to 1944 Germany with the atomic core. Rufus informs Wyatt and Agent Christopher of Flynn's location and time, explaining that Flynn probably wants to give the nuclear bomb to the Nazis before the end of World War II. Before the mission, Mason shows the time team the new wardrobe dock, which is full of clothing from different eras.
When the time team the mission to Mason and Agent Christopher, the team and Mason are delighted to hear the similarities to it and a James Bond film which did not exist in the original timeline. Agent Christopher however, wants to stay on topic and asks the team if they saw any trace of the atom bomb. They did not see the bomb on the mission, and begin theorizing that Anthony may be using it as a fuel source for the Mothership. Lucy demands two things of Agent Christopher. Lucy needs an excuse for leaving her job and that Mason Industries be working on a solution to get Amy back. If these conditions are not met, Lucy threatens to leave the project.
Agent Denise Christopher introduces Patrick Ramsey to Wyatt, explaining that Ramsey was her boss when they worked at the National Counterterrorism Center. They plan to replace Wyatt with Master Sergeant Dave Baumgardner, due to Wyatt's inability to kill Flynn. As Wyatt is informed of this, Flynn takes the Mothership to March 2, 1836. Baumgardner won't arrive in time to go on this mission, so Wyatt is to go on one final mission.
When the time team returns, Christopher and Ramsey relieve Wyatt of his duties and near brief Baumgardner on the existence of time travel. Lucy and Rufus stop Wyatt from being replaced by refusing to continue on time travel missions without Wyatt, because they trust him.
1972 - Episode 6: "The Watergate Tape" Edit
Agent Christopher gives the time team press credentials to get into the White House in 1972 for when they go back in time. Christopher mocks the appearance of Wyatt's disguise before the time team goes to 1972 to stop Flynn from obtaining the missing eighteen and a half minutes of Richard Nixon's Watergate tape.
By the time team's belated return to the present, Jiya, Ramsey, Mason, and Agent Christopher are able to determine that the Lifeboat has been jeopardized. Agent Christopher tasks Ramsey with getting men down to Mexico to stop Flynn in the present day.
Mason and Christopher prepare to use a protocol they came up with earlier to locate the Lifeboat in case of emergency. At Mason Aviation, Christopher overhears a suspicious phone call between Mason and Benjamin Cahill.
As part of the protocol, the time team buried a capsule with a message inside of it with details on how to save them. Agent Christopher was able to close down a street by claiming she was with the Centers for Disease Control and Prevention and a Zika mosquito was found in the area. Using the excuse, the capsule was recovered secretly, but the paper inside was weathered and ruined by time. Tests were run on the note, and the only words that can be made out are "DEATH" and "MILLENNIUM." Later, Jiya explains to Christopher and Mason that she's filled in Rufus' blanks and is able to determine there was a problem with the Lifeboat's navigation system. Jiya figures out a successful solution to bringing the Lifeboat back to the present safely.
Later, Agent Christopher gets authorization from Patrick Ramsey for a surveillance operation on Connor Mason. Agent Christopher begins to grow suspicious that Mason is hiding something from her.
1969 - Episode 8: "Space Race" Edit
Agent Christopher gives Lucy, Rufus, and Wyatt badges that will give them access to Mission Control at NASA in 1969. Lucy complains that she won't be able to get much done while disguised as a secretary but Christopher assures her that it's the best Mason Industries can provide her.
When the time team returns to the present, Agent Christopher shows them the unredacted file on Garcia Flynn, against the wishes of her boss. In the file they are able to find out that Maria Thompkins is Flynn's mother and Gabriel Thompkins is his half-brother. Christopher provides the team with more information about Maria and Flynn's father, Asher Flynn. Christopher confirms to Lucy that after Flynn is eliminated they will work on bringing back Amy.
1934 - Episode 9: "Last Ride of Bonnie & Clyde" Edit
Agent Christopher speaks on the phone to her daughter ordering her to go to the ballet recital when she is interrupted by Lucy, Rufus, and Wyatt who are awaiting details about their next mission. Christopher tells them that Flynn has gone to 1934 Arkansas, and that they have a photograph gained from a raid on Flynn's base. The photo is of a mysterious key. They also found a note that was in the briefcase Anthony had in Houston, which contained the date May 22, 1934 and the phrase "Rittenhouse key." Based on the evidence, it is assumed that Flynn is going back to obtain the key. Christopher said she's been trying to find out something about Rittenhouse since they got back from the Hindenburg mission but hasn't been able to find any information.
As the time team leaves, Connor Mason enters. Mason appears to just be checking up on Agent Christopher and seeing if she has everything she needs, but is acting suspicious. Later, Mason suggests that Agent Christopher use Mason Industries' analytical tools to examine the evidence gained from Flynn's warehouse. Agent Christopher dismissively agrees to but explains that he will need to raise his clearance level and that there is a lot of red tape. Agent Christopher does not trust Mason.
Later, Connor Mason and Benjamin Cahill have a conversation about Agent Christopher outside their cars in a remote location. Mason tells Cahill that Agent Christopher's investigations of Garcia Flynn's equipment has gotten her to start looking into Rittenhouse. Cahill advises Mason to dissuade Christopher's investigation of Rittenhouse or else Rittenhouse will kill her. Agent Christopher had been watching the whole meeting take place, and captured pictures of Benjamin and Mason.
The time team returns from 1934 without the key they set out to get and without any information regarding the key. This upsets Christopher. Later that night, Agent Christopher tracks down Rufus at a restaurant and Rufus tells her everything he knows about Rittenhouse.
1780 - Episode 10: "The Capture of Benedict Arnold" Edit
Agent Christopher invites Lucy over to dinner with her wife, Michelle Christopher. After dinner, Agent Christopher gives a flash drive full of pictures and information about her children in case any of the missions through time accidentally somehow erases their existence.
1893 - Episode 11: "The World's Columbian Exposition" Edit
When Rufus and Wyatt return to the present, Wyatt demands to know where the Mothership is. The Mothership had gone to many locations in a short time . Wyatt announces to Mason, Jiya, and Agent Christopher that Flynn had captured Lucy in 1780. They go to 1893, which was the last time period the Mothership traveled to.
1882 - Episode 12: "The Murder of Jesse James" Edit
Agent Christopher sends the time team off on a mission to find out whatever it is Flynn wants to do with the outlaw Jesse James and stop it. When the time team returns to the present, Rufus tells Mason and Denise that Emma Whitmore, a time machine pilot thought to be dead, is still alive and that she's now working with Flynn.
1983 - Episode 13: "Karma Chameleon" Edit
Agent Christopher is furious that Wyatt and Rufus stole the Lifeboat to save Wyatt's wife, Jessica Logan. She's also angry about Lucy's complacency in the theft and of how reckless the action was. Agent Christopher wanted Lucy to tell her about the theft ahead of time, but Lucy is still angry and distrusting of Agent Christopher because of her inaction in the attempt to bring Amy back.
While Wyatt and Rufus are in 1983, Anthony calls Mason Industries wanting to talk to Rufus. After finding out Rufus isn't available he says he'll only talk to Lucy. Mason thinks the request is ridiculous and tries to pick up the phone, but Christopher insists that only Lucy talk to Anthony and demands that Lucy keep Anthony talking. Anthony tells Lucy to meet him. Mason is against Lucy and Anthony meeting, but Christopher encourages it, despite knowing the risk.
Jiya puts a tracking device on Lucy for her and Anthony's meeting. Anthony suspects this, finds the tracker, and wraps it in foil to prevent it from finding their location. Anthony then plants it on a random civilian.
Later, Lucy tells Christopher what Anthony told her in the meeting and convinces her that destroying the time machine after Amy is brought back would be the best course of action, assuming Anthony follows through with destroying the Mothership. Christopher refuses discussing Anthony and Lucy's meeting with Mason, knowing he'd oppose the Lifeboat's destruction.
Anthony was unable to follow through with the destruction of the Mothership because he was killed by Flynn. Agent Christopher tells Anthony's family he died in an accident serving his country.
1927 - Episode 14: "The Lost Generation" Edit
Agent Christopher talks with Wyatt in a black site in a national park. Wyatt was being imprisoned there for stealing the Lifeboat. Despite her anger, Christopher tried to get Wyatt the JAG defense lawyer Sam Wyer, who according to her was good at his job. Wyatt denies the offer, saying he deserves the punishment he's receiving.
In a remote warehouse, Christopher, Lucy and Rufus meet up. Lucy confesses to them that Benjamin Cahill is her biological father. Agent Christopher does not approve of her meeting with Cahill, because it put her in serious danger. Agent Christopher informs Lucy and Rufus that Flynn traveled to May 21, 1927, and that they'll have to complete the mission without Wyatt. Lucy suggests not stopping Flynn from changing history, because Rittenhouse is too dangerous a threat. Rufus convinces Lucy, that despite Rittenhouse's planned attempts to go back in time and grow in power, Flynn is still dangerous and needs to be stopped. Christopher introduces Lucy and Rufus to Master Sergeant Dave Baumgardner, Wyatt's replacement, before they go on their mission.
Later, the NSA and Rittenhouse takes over the time machine project at Mason Industries due to the theft of the Lifeboat. Agent Jake Neville replaces Agent Christopher.
Agent Christopher meets with Wyatt again. Wyatt apologizes for making Christopher lose her job and warns her that the NSA has likely been plotting a non-hostile takeover for a long time now. Christopher hands Wyatt a confession form which she warns if he signs, he will disappear. Before Agent Christopher leaves, she sneaks Wyatt a paperclip to escape with.
Christopher, Wyatt, Lucy, and Rufus all meet up in the warehouse. Christopher reveals that the people in control of Mason Industries are Rittenhouse. They all decide to unite and fight against Rittenhouse.