Main characters
Darien Fawkes (Vincent Ventresca)
Darien Fawkes is a former career criminal and catburglar, who received multiple misdemeanor convictions and two felony convictions before he was thirty. Darien is described as having an "above-average intellect", and capable of being very deceptive. He and his brother Kevin were raised on a farm by their aunt and uncle after their mother died and their father left them (it is later learned that their father was a sniper for the government and after his cover was blown, he left his family in order to protect them). While Kevin became a scientist, Darien began a career as a thief while still in his teens. After being caught because he stopped to give CPR to a heart-attack victim, he was sentenced to life in prison without possibility of parole under California's three strikes law. This was where his older brother, Kevin, stepped in.
Kevin was a research scientist who had been working on a top-secret project. He cut a deal with his bosses to get Darien out of prison in exchange for using him as a test subject. When Darien agreed, he was then implanted with the Quicksilver gland, but Kevin's rush to remove Darien from prison meant that he implanted the gland before devising a way to remove it without killing the recipient. One of the other scientists, Arnaud DeFehrn, was actually a terrorist that had infiltrated the project, and led an attack on the research facility that caused Kevin's death and the loss of most of the project research. Darien escaped but was unwillingly drafted into The Agency, who had funded the project.
In exchange for the counteragent, he needed to stay sane, Darien agreed, albeit reluctantly, to be an agent under their employment. Upon working with The Agency, Darien develops an affinity for his co-workers and opts to continue working there even after his dependency on counteragent is cured by Claire.
He has high morals for a career criminal – he could have easily escaped after his final break-in except he surprised the elderly owner into a heart attack, and stayed behind to perform CPR (unfortunately, the officers who caught him and the elderly man himself thought he was molesting the latter). He is a highly talented thief with expert-level breaking and entering skills, learned from his many incarcerations, and finds these skills quite useful in his new career as an espionage agent. His trademark expression is "Oh, crap.", usually said when he realizes he just got himself in trouble, although he also has a habit of quoting various other sources at least once in each episode (albeit in the form of a voiceover).
On one occasion, Darien was briefly possessed by the personality of Simon Cole, the previous owner of the gland, after Cole's residual RNA took over his body thanks to the imprint of his personality left in the gland, causing Darien to see Cole when he turned his eyes invisible and briefly act as him. Darien later attempted to use this 'quirk' of the gland to transplant his brother's RNA into his mind so that Kevin could work out a way to remove the gland or fix the quicksilver deficiency, but Kevin was unable to cure the madness and chose not to arrange for the gland to be removed as he felt it made Darien a better person.
Due to the gland, Darien has various powers beyond being able to simply turn invisible; he can turn his eyes invisible and see in infrared, his body temperature lowers to a point where he can cool drinks while invisible and escape heat-seeking weapons, he can turn others invisible so long as he remains in contact with them, and he can even turn parts of his body invisible while leaving the rest of him fully visible (Allowing him to, for example, pretend to be a double-amputee to infiltrate a hospital, or turn his head invisible to give the impression that he has killed himself to catch enemies off-guard).
Robert Albert Hobbes (Paul Ben-Victor)
Robert "Bobby" Hobbes is one of the agents working for the Agency, easily the most experienced and thus their most highly capable asset in the field, right next to Darien's invisibility powers. He is given Darien as a partner when Darien joins the Agency. At the start of the series, Hobbes has been at the Agency for several years, as The Official hired him when his quirks and mild manic depression had gotten him tossed out of every other government intelligence agency. Despite the Agency being his last chance at government work, Hobbes feels underappreciated there, receiving very little pay and being sent on mostly unfavorable missions. Despite his mistreatment at The Agency, he displays a strong loyalty towards it as displayed by his unwillingness to accept a position at the FBI for a higher salary.
His relationship with Darien begins somewhat badly, with Darien being new to undercover missions and frequently blowing their cover while nevertheless earning far more than Hobbes, but they eventually become close friends, displaying a willingness to sacrifice their lives for each other on several occasions. They often banter with each other, much to the annoyance of those around them. Hobbes seems to enjoy using guns, constantly carrying at least one on his person at all times. He frequently pulls it out and threatens people with it, often referring to it as his "insurance policy". He frequently refers to himself in the third person, which is often mistaken for arrogance. He is a former U.S. Marine who served in Operation: Desert Storm, and in addition to his Marine Corps hand-to-hand combat training, is also an expert in the Korean martial art Hapkido, although in one episode he describes his skill as a "Grand Master of Wushu", trained by the CIA. In more than one episode, Hobbes has disarmed and knocked out as many as three armed combatants. Hobbes displays signs of extreme, sometimes comical paranoia in most cases, acting as if the world is out to get him. He frequently runs background checks on people he's suspicious of, and is not above stalking people to see if they are up to anything. Being trained by the FBI and the CIA, he is excellent at spying and information gathering, both of which only serve to make his paranoia worse.
Charles Borden a.k.a. The Official (Eddie Jones)
Charles "Charlie" Borden is the long-time head of The Agency. Most of his background is unknown, due to Borden's refusal to divulge information about himself to his agents (for instance, Darien first learns Borden's name upon hearing two U.S. Marshals place Borden under arrest). He has been the head of the Agency for an indeterminate time, but it is insinuated from photographic evidence that he has served in this capacity since at least the Kennedy administration. He typically expects his orders to be carried out with no argument from Darien, Hobbes, or Claire, usually dismissing any of their questions or concerns out of hand. The Official is concerned with two things above all else: carrying out the missions he is entrusted with - despite his frustration at the constantly shifting nature of the Agency's funding due to their low budget - and keeping an eye on the Agency's bottom line.
Albert Eberts (Michael McCafferty)
Albert Eberts came to the Agency from the IRS, and serves as both assistant to The Official and the Agency's bookkeeper. He usually conducts Darien and Hobbes' briefings, frequently going into more detail than The Official deems necessary and being told: "Shut up, Eberts." He is highly skilled in the use of computers and also displays a proficiency in martial arts.
Dr. Claire Keeply a.k.a. the Keeper (Shannon Kenny)
Claire is The Agency's resident medical doctor and researcher, and was a minor researcher on the team that did preliminary work for developing the Quicksilver gland. She is responsible for monitoring Darien's health and compiling data on long-term usage of the gland. She is also the one who mixes and administers the counteragent serum. She does not particularly care for Darien at first, possibly because he reminds her of Kevin (who she had been romantically involved with before his death) although eventually she and Darien become friends; Claire even risks her career to cure Darien permanently of Quicksilver Madness. There are hints of romantic tension between her and Hobbes.
Alex Monroe (Brandy Ledford, season two)
Alex Monroe is an addition to the cast in the show's second season. She is a federal agent working for the Agency and is regarded as one of the finest agents overall. In addition to her skills as a deep cover operative, she is an avid martial artist and amateur profiler, skills that she has used to build a strong network of friends and spared enemies who frequently supplement her resources at the Agency with top-of-the-line equipment. She has top security clearance and is the sole agent that has her own office in the Agency. In doing so, she initially earns the ire of Bobby Hobbes, who covets the comparatively lavish budget and equipment that she enjoys. This eventually expands into a full blown rivalry between the two, though it later becomes more friendly as their respect grows. Before the end of the series, she fully trusts Hobbes as a reliable back up in any mission, particularly after Hobbes demonstrates his proficiency in next-generation surveillance equipment and shows superior marksmanship. She has a personal vendetta against a group called "Chrysalis", who used her as a surrogate mother to produce a genetically engineered son. After birth, they took her son, and she has been looking for the group ever since. She eventually finds the baby but then decides to let his biological mother (Jarod Stark's wife Eleanor, the former being also the baby's biological father) keep it, sensing her feelings about him to be genuine and her wishing to defect from Chrysalis (though, unbeknown to the Agency, the latter is untrue). Even after this, Alex decides to stay with the Agency.
