Ducky's Entire NCIS Backstory Explained

After nearly two decades, hundreds of cases, and dozens of agents who have come and gone, there are a scant few NCIS characters still on the show who have been there since the beginning. One of those perennial members of the team is Dr. Donald "Ducky" Mallard (David McCallum), who served as the chief medical examiner before retiring and taking over the position of NCIS historian. Being the most senior of all the NCIS squad members by decades, ol' Ducky has quite a history of his own.

With a penchant for treating his colleagues (and cadavers) to long, detailed, and often rambling stories of his past, viewers have been able to glean a decent amount of information about Ducky's backstory. And contrary to his kindly demeanor, some of it is quite dark and disturbing. From his early school years to the wartime deployments that left him deeply emotionally scarred, this is what Ducky was up to before viewers met him on NCIS.

Despite working for a U.S. law enforcement agency, Ducky was born in Scotland to Joseph and Victoria Mallard (Nina Foch), the latter of which lived an extraordinarily long life before dying of Alzheimers during the show's seventh season. Ducky went to Eton College, a boarding school in England which also claims Princes William and Harry, James Bond author Ian Fleming, and House star Hugh Laurie as alumni. For his medical training, he studied at the storied University of Edinburgh Medical School.

As he reveals in the season 2 episode "Bikini Wax," Ducky considered going into teaching after he graduated from the University of Edinburgh, but, in a bit of irony, didn't think he was suited to delivering "those long, rambling, esoteric lectures." Instead, he became an officer in the Royal Army Medical Corps. The job would see him traveling to war zones all over the world, and would unfortunately result in him enduring several traumatic events.

Despite being sent to some of the best schools in Great Britain, Ducky's family life was marked by chaos and difficulty. His parents divorced, and after his father remarried, he had another son, Ducky's half-brother Nicholas (Andy Walken). Neither Ducky's father nor his step-mother were particularly adept at parenting, so Ducky often found himself caring for his younger brother. He believed his brother to be long dead, until the episode "Spinning Wheel" from the show's 13th season. During an investigation, Ducky discovers that his brother changed his identity and immigrated to the US, but by the time the two are reunited, Nicholas is unfortunately suffering from early-onset Alzheimer's.

His mother didn't have much luck in love after the divorce. During flashbacks in the season 14 episode "The Ties That Bind," we learn that Ducky's mother was briefly involved with a conman. Young Ducky (Adam Campbell) chased the philanderer off, only to later discover that his mother knew what type of man he was, but insisted that they were in love, all the same.

Ducky himself was no stranger to bad romance early in his life. Season 12's "So It Goes" details a love triangle between Ducky and two close friends, which ends with the young doctor heartbroken and moving to America, and the two friends getting married.

As difficult as his family and love life might have been, nothing compared to the horrors he encountered during his various stints in the armed forces.

NCIS viewers may have been under the impression that Ducky was nothing more than an affable army doctor with a sterling record. However, that all changed in the season 6 episode "Broken Bird." While at a crime scene on a city street, a woman comes forward from the crowd and stabs Ducky in the hand while accusing him of murdering her brother. To the rest of the NCIS team's dismay, Ducky confirms that she's not wrong to make the accusation.

However, it's significantly more complicated than a cold-blooded killing. While serving at an army base in Afghanistan during the Soviet-Afghan War, Ducky was charged with treating Afghani detainees who kept coming to him with brutal injuries. He eventually learned that one of his colleagues at the base was conducting cruel interrogations, torturing the prisoners for information, even when it was clear that they had none. One prisoner was sent to Ducky routinely with severe wounds, and eventually, Ducky made a difficult decision. Realizing that the man was likely destined to be tortured to death in these interrogations, Ducky instead administered a lethal dose of morphine to put him out of his misery.

This horrific episode from Ducky's past almost got him charged with war crimes. However, after he was able to explain himself, the charges were dropped. Despite being cleared, Ducky wasn't able to fully forgive himself. 

The incident in Afghanistan wasn't the last time Ducky found himself making a painfully difficult decision. During the Bosnian War, Ducky was working with a UN task force, as he outlines in the season 5 episode "Tribes." As part of that duty, he had the unenviable task of performing autopsies on the bodies of Muslim children discovered in a mass grave. He felt extra heartache about the job because the parents of the children didn't want autopsies to be performed on them, as they thought it constituted the desecration of their bodies. Ducky felt bound by his duty to continue, although going against the parents' wishes never sat well with him.

Sometime in the '90s, Ducky joined NCIS, where he began working with Leroy Jethro Gibbs (Mark Harmon), with whom he would go on to have a decades-long friendship.

The season 13 episode "16 Years" gave viewers a taste of another intriguing piece of Ducky's backstory. Thanks to the discovery of a body linked to a cold case, viewers learned that in addition to his crime solving duties at NCIS, Ducky is also a member of a secret amateur sleuthing group called Sherlock Consortium for Investigation. Also a member of that particular consortium? The acerbic Judith McKnight, played by Jessica Walters with a sensational Lucille Bluthian flare.

Out of all the moments in Ducky's backstory, that's the prequel spin-off that should be getting the green light.