Grisha Alexandrovich Nikolaev-Callen (G. or Callen to his NCIS colleagues or Mr. Callen via Hetty Lange) is an NCIS Special Agent and also a member of the Office of Special Projects Team in Los Angeles as well as the lead agent of the OSP field team and partner of fellow NCIS Special Agent, Sam Hanna.
George Callen, his maternal grandfather, was an OSS agent stationed in Romania during World War II. He killed members of the Comescu family because of their war crimes. This caused a blood feud, with the Comescu family vowing revenge against his entire family.
As such, George was later murdered with Clara attempting to flee to the United States with her two young children with the assistance of Henrietta Lange who was Clara's handler.
Hetty was ordered to abort the rescue mission at the last minute. Unfortunately, two assassins working for the Comescu family arrived on the beach in Romania and while one distracted young Callen by giving him a toy soldier, the other murdered Clara. It is unknown why Callen was spared, but this was later declared a mistake by Alexa Comescu - the last head of the family.
The trauma associated with these events resulted in Callen suppressing the memories for many years.
No one knows how Callen and Amy came to the States, but the two children were placed in separate orphanages. Hetty admitted in Deadline that it was two years before she even knew they were in the US, and by then Amy was deceased.
In 1975, at just five years old, Callen was removed from the orphanage and subsequently transferred to the foster care system in the State of California while Amy remained in the orphanage she had been first placed into when she had arrived in the States. Hetty was the one who had him placed in each of the foster homes, determined to find him a good family.
For the next thirteen years, Callen lived with thirty-seven foster families, experiencing various problems which in turn left him emotionally damaged and incapable of trusting other people.
In one family, had a foster sister named Alina Rostoff.
In another family, he met his foster brother, Raymond Lewis who once defended him from a bully but when he ended up assaulting the bully, winding up in Juvie, doing a brief stint and Callen would not see Raymond for many years and was placed with a new family weeks later.
While in another foster family, Callen had a foster mother who was an alcoholic while the father was kind and a carpenter with the unnamed foster father tutoring Callen in carpeting.
Callen also served as a lifeguard while in high school.
Upon becoming a teenager, Callen regularly got into trouble. He ran away from his last foster home and robbed a storage locker, only to get caught which led to him receiving a three week sentence at a prison for juveniles.
Due to his smart-mouth attitude, the guards also beat Callen who later escaped and stole a car but he ended up crashing into a pole and was arrested once again.
Hetty arrived at the scene, "rescuing" him and took her under her wing with Hetty also training Callen.
Upon turning eighteen, Callen enlisted in the United States Army although his history and what rank he held remains unknown. This ended up straightening out his attitude and he moved past some of his issues.
Some time either before or after that, he volunteered as a wildlife firefighter.
At the age of twenty, Callen fired a gun for the first time.
Following his military service, Callen became a federal law enforcement officer serving in various agencies with the Central Intelligence Agency (CIA), the Drug Enforcement Agency (DEA), and the Federal Bureau of Investigation (FBI) before joining NCIS.
He worked with NCIS Special Agent Leroy Jethro Gibbs on a few missions.
While undercover with Tracy Keller Rosetti, he was briefly "married" to her.
At some point during his tenure at NCIS, Callen presumably conducted assignments or worked at other locations before being reassigned to the Office of Special Projects in Los Angeles where he also went through a series of partners before he was ultimately partnered with Sam Hanna.
According to Henrietta Lange in Bounty, Callen and Sam Hanna didn't trust each other properly until New Years Day in 2007. At that point they had been partners for less than a month, and it wasn't going well. Callen went undercover to meet an Armenian mob boss and Sam was assigned as his backup. Sam was caught by a sentry and the mob boss handed Callen a gun and demanded Callen shoot Sam as proof of loyalty. Callen aimed and fired his gun right at Sam's head because he knew the gun was empty due to its weight.
NCIS Season 6
Callen made his debut appearance in the NCIS Season 6/NCIS: Los Angeles backdoor pilot episode, Legend (Part 1).
He was introduced ignoring a call from his boss, NCIS Special Agent Lara Macy before he spoke to his old friend, fellow NCIS Special Agent Leroy Jethro Gibbs.
The two spoke for a while about the past they had shared together although they were interrupted by a young Russian woman cycling by.
After they had finished, Callen left to go get ready for the second undercover operation he would play a main role in.
NCIS: Los Angeles Season 1
Callen appeared in the NCIS: Los Angeles Season 1 premiere episode, Identity where he was first seen in a small room, presumably at a B&B, remembering the near-fatal shooting.
It was shown that he had been left with five permanent bullet scars on his back as a result of being shot four months earlier.
He then proceeded to get dressed and ultimately leave the B&B, heading to Venice Beach where he bought coffee from a local vendor just as Sam arrived in his Dodge Challenger.
NCIS: Los Angeles Season 2
In the Season Two Premiere, Hetty makes arrangements for Callen to purchase a house of his own - the same house where he lived with Alina Rostoff as a foster child.
This season mostly revolves around Callen, who has been stalked by someone he does not know. He sees someone near the grave of his sister, and over the course of the season, runs into people who seem to know more about his past than he does. When Hetty resigns and takes off to Prague, Callen finds out from Director Vance that Hetty has started her own investigation “Operation Comescu”, which is all about Callen. Callen and the OSP Team then resign when Vance refuses to fly them to Prague to get Hetty. Arriving in Prague, the OSP Team discovers that Hetty has been taken by The Comescus’ and that The Comescus’ have been in a decades-long blood feud with the Callen's, one of which Callen is the last. The OSP Team tracks their safe house down to a house on the beach, and Callen starts to remember things from his past, as he realizes he has been there before. Inside, Hetty fails to convince Alexa Comescu, the matriarch of the family, that Callen died 3 weeks ago, showing her a clip of the assassination attempt and a false death certificate.
NCIS: Los Angeles Season 3
In the Hawaii Five-0/NCIS: Los Angeles Crossover Episode, Callen traveled to Hawaii with Sam after learning that Dracul Comescu, who was now on the NCIS: LA most wanted list, was seen in Hawaii.
NCIS: Los Angeles Season 4
Callen goes to Iran to capture Marcel Janvier aka “The Chameleon”. He forces him to set up a meet with a Russian arms dealer, Isaak Sidorov. The Chameleon gives up Callen's partner, Sam. Callen is furious and sends Kensi and Granger to find Sam.
NCIS: Los Angeles Season 5
NCIS: Los Angeles Season 6
Callen and Sam are trapped in and underwater submarine that is headed for an aircraft carrier. The sub has been made into a torpedo and they are going to explode with the sub. They bust a hole in the sub to make their captors open the locked compartment they are trapped in. They then kill their captors and escape. The Navy blows up the sub just as Sam and Callen escaped. They blew it up because there were terrorists aboard.
NCIS: Los Angeles Season 7
NCIS: Los Angeles Season 8
When Callen is not solving cases or covering with a mole inside the OSP, he is dealing with a problem he never expected to have: a living family. His father, now in the U.S., had another lover after Grisha and Amy's mother, and she had a daughter, Alexandra Reynolds. Despite being a company based in a mole search. That ended up failing Alex's ex, who first knows his son's grandfather when the older man abducts him. This is a strain on Callen's relationship with Nikita. This is partly because Callen has to give up a professional integrity for Nikita to jail and partly because his secrets, first approach to interpersonal communication between himself, separated from Alex and his son; do not work. To start a relationship with Alex, Callen and Nikita appear at Alex's house. When Jake then says the oven has subsided, Alex invites them both to dinner.
NCIS: Los Angeles Season 9
In Season Nine, sometime following the events of the Season Eight Finale, Hetty has disappeared, apparently having retired from NCIS for good and sold most of her properties and taken her boat. Following Hetty's departure, Executive Assistant Director, Pacific Operations Shay Mosley appears to take her place and oversee the team. Throughout the season, Callen and the team are concerned regarding Hetty's disappearance and begin to try and locate her. Eventually, it’s revealed Hetty traveled to Vietnam to rescue Harris Keane, a former member of her CIA Unit during the war that Hetty thought was dead but later finds herself captured by a human trafficker and criminal Dang. Hetty’s survival was confirmed by a joint operation combining the OSP team as well as Hetty’s former CIA Unit in Vietnam, with Keane and Hetty both making it out of Vietnam. Hetty resumes her duties as Operations Manager, but finds difficulty working with Shay Mosley who intends to break up the team.
In the Season Nine Finale, Callen, along with the rest of the team, learn the truth about Mosley's kidnapped son and Callen's promise to help her when they come into contact with a suspect on a current case who is connected to Mosley's former lover, Spencer Williams. Upon learning this information, Mosley sees this as her best chance of finding and getting her son back. Mosley and the team learn they are in Mexico, but the off-the-books Mexico mission to rescue Mosley's son was highly dangerous, putting the team at risk. Even though Deeks is fired by Mosley after confronting her about her unfair, reckless, and disrespectful behavior, Deeks still joins the team on the off-the-books Mexico mission (unsanctioned) to save Mosley's son. However, while the mission is successful, reuniting Mosley with her son and returning them to LA, the rest of the team are struck by an RPG while escaping in their SUV, leaving uncertain who is dead or alive.
NCIS: Los Angeles Season 10
Shortly after the Season Nine Finale, Callen and the team are revealed to have survived the impact that hit their SUV. Kensi is the least injured member of the team, but becomes extremely worried when Deeks remains unconscious following the explosion. The team are forced to separate so Callen & Sam take a dirt bike as far as it can go. After the bike cuts out, they walk through the desert to find safety and shelter. Eventually, Callen & Sam run into a kid who leads them to shelter then finds help, the kid came back with his parents who manages to get to a hospital. Callen & Sam regroup with Kensi, Deeks & Turk and while Callen, Sam & Deeks are in the ER, Kensi & Turk stand guard outside and get ready for a fight from Spencer Williams’ men who are hunting them. At the last minute, Mosley confronts Williams with duel wield pistols aimed at him telling him “Stand Down” after telling Mosley “No” she shoots him and tells his bodyguard to call it off because now that he’s dead no one's getting paid so they did. Afterwards, the calvary that Hetty sent arrives and evacuate the team to Balboa Naval Hospital.
After being shot, Callen was forced to take some time off. During this time, his sister asked him to watch her son for the day. Despite still being upset with him, she was worried to hear he was shot but he told her that he was fine. Calen spent the day with his nephew will initially being awkward but he was able to bond with him by teaching Jake how to play cards and allowing him to help Kensi and Deeks. When Alex shows up to pick Jake up, she is angry at Callen that her son was at Deeks' bar but is relieved when Deeks tells her that he had him fix up the tech for the fundraiser. Jake tells her about his day while begging for his uncle to come over, something she ponders on after Callen previously asked to be welcomed back into their lives because they are family. While she gives no answer, she is grateful that he looked out for Jake.
Although Joelle and Anna believe Volkoff had a point, Callen was not moved and coldly left the pleading man for dead. Callen subsequently took his father to a hospital where it is revealed he had a lung infection. Following his return to America, Callen was able to contact Alexandra and Jake who visited Nikita in the hospital while he was dying of a lung infection. Much later, Callen discovers Nikita removing his IV tubes and tries to stop him but Nikita tells him that he does not have that much longer to live but does have one final request to see his daughter not Alexandria but his late daughter. Callen wheels his father to the grave of his sister Amy in there Nikita pays his respects. He shares one final happy moment with his son by thanking him for bringing him home. Sometime later, Nikita succumbs to his infection and dies. As a final act of respect, Callen has his father buried next to his sister. Callen later visits the grave pays respect by putting one of his father's coins on top of the grave before leaving.
NCIS: Los Angeles Season 11
Callen is reunited with Anna who shows him something, he did not expect. It was his surrogate brother Darius Comescus who survived the gas leak.
During the raid of the house, Callen was attacked with a syringe but overpowered his assailant but the drugs caused him to hallucinate to when he lost his mother. However he is able to snap out of it and re-join his team and attacking the Smugglers. He comes across Darius and his fiancé when Darius notices that he has a strange look in his eye and reaches for his gun, Callen regained his wits and shot a smuggler who was sneaking up on him. This relieved Darius who reunited with his fiancé.
Callen later finds Hetty at the cemetery where they watch Darius visit his surrogate father's grave and mourns the death of Nikita. Callen and Hetty watch the scene and discuss what Darius intends to do next.
NCIS: Los Angeles Season 12
He is reunited with his former foster brother Raymond Lewis who are first does not seem to recognize him but after a while recognized his name and said he thought he looked familiar. After a day of catching up, Callen was able to get Louis off the hook with his recent actions but it turns out the Louis was unknowingly caught up with drug smugglers who intended to kill him for being pulled over and for potentially notifying the feds about them. Callen defended Louis by taking down to Doug's but the leader had managed to slip away it was about to kill Lewis' wife until Lewis got the drop on him and knocked him out
NCIS: Los Angeles Season 13
In episode Subject 17 he learns about Hetty's program training orphans as agents and all the files about it. Hetty admits that he is subject 17. She felt before they could discuss it further.
Having been left psychologically damaged as a result of his upbringing, Callen is a man who sometimes to prefer to work alone, leading others to regard him as a lone wolf which in turn can often clash with his partner, Sam Hanna who as a Navy SEAL believes that they should be working together.
In spite of that, Callen is very dedicated to his work as an NCIS Special Agent and takes any kind of case, especially one concerning a fellow NCIS agent very seriously.
Callen is a man in his late thirties, early forties with short brown hair and blue eyes.
While participating in a raid, Callen dons an NCIS bulletproof vest with the words "NCIS" in the centre of it with the vest covering his entire upper and lower chest area. He also wears a holster containing his SIG around his right thigh just above the knee.
As of the NCIS: Los Angeles Season 7 episode, Angels and Daemons (episode), Callen wears a new version of the bulletproof vest but this one is much smaller than its previous counterpart and only covers the centre of his chest.
As an NCIS Special Agent and the leader of the OSP field team as well as a former CIA officer, Callen is a highly skilled agent whose abilities make him a valuable asset to both NCIS and OSP.
He is multilingual, being fluent in at least six other languages: Spanish, Polish, Russian, German (which is claimed to be Austrian, and is usually completely butchered), Italian (with a Northern accent), and French. He also claims to know Czech and Romanian. He can also read Arabic.
Despite not having an adept for technology, Callen is often seen using computers to either write up reports regarding a case or searching for a missing friend.
Callen is skilled at interrogation.
Like all NCIS agents, Callen is trained to use a firearm and can fire a single round from his SIG-Sauer, one that could non-lethally injury a suspect or kill one.
As the leader of the Office of Special Projects field team, Callen is responsible for issuing many of the commands and orders that his fellow colleagues will carry out such as heading to a crime scene or searching for any possible evidence.
Like NCIS Special Agent Nicholas Torres of the Washington D.C. NCIS Major Case Response Team, Callen is a skilled pickpocket, able to steal any item without others detecting him This was best seen when he successfully stole the badge of DEA Banuelos and gun of FBI agent Carole Gordon.