David Marcus David Marcus was a male Human scientist in the 23rd century . Born in 2261 to James T . Kirk and Dr . Carol Marcus , he grew up in a single - parent environment with his mother , immersed in a world of scientific research . David knew Kirk , but never met him , because his mother effectively banned Kirk from his life ; she felt they lived in two different worlds , and she wanted David in hers . David ' s professional choices were heavily influenced by his mother ' s status ; by the age of twenty - three , he had earned his doctorate and soon became a member of his mother ' s research team . In 2284 , David began work on Project Genesis with his mother , stationed on Regula I . As they progressed , traces of his father showed in David ; he was impatient for results and eager for solutions . This led him to employ protomatter , denounced by many scientists as hazardous and highly unstable . Nevertheless , it appeared to solve the problems . In 2285 , David ' s closeted scientific world was interrupted when Khan Noonien Singh took control of Pavel Chekov and forced him to announce that he was taking Genesis away from Carol ' s team on orders from Kirk . This threat was part of Khan ' s ruse to lure Kirk to them , and it provided the volatile backdrop to the first meeting between father and son . He fled with his mother to the Genesis cave to hide their research from Starfleet . Khan could not find them , but Kirk arrived afterwards and knew to look for them there , beaming down . This encounter actually began as more of a confrontation ; David displayed the same eagerness for action as his father when he attacked the admiral with a knife , presuming that Kirk ' s intent was to take Genesis . Carol intervened , and it was after seeing her that Kirk guessed David was his son . David got a chance to see his father in a more positive light when Kirk battled it out with Khan . David remained on the bridge of the , acting as advisor on the Genesis wave , and was impressed by his father ' s courage and abilities . After this brush with death , David showed his compassion by trying to comfort the man he once despised , when Kirk was grieving over the death of Spock . David apologized to Kirk for misjudging him and added , " " I ' m proud , very proud , to be your son . " " ( ) Shortly afterward , David was assigned to the with Lt . Saavik to study the planet created in the Genesis explosion . At first , he was thrilled with the array of environments , but when he beamed down for a closer look , he found the planet in a state of environmental chaos , and recognized the cause as being the protomatter ' s instability . David ' s naivete showed through when a group of Klingon s arrived and demanded the Genesis Device . He honestly believed the Klingons wouldn ' t harm them because , as a planet - building device , it was an obvious failure . To the Klingons , however , Genesis was a powerful weapon , and a hostage was selected to die as proof of their serious intent . As a " d ' k tahg " knife was raised to Saavik ' s neck , David lunged toward the Klingon in a burst of courage which might have been expected of his father . However , he lacked Kirk ' s fighting prowess , and was killed with a single thrust of the three - bladed knife to his chest . ( ) The memory of David ' s death at the hands of the Klingons embittered Kirk for years afterward and colored his attitudes during events leading to the Khitomer Conference in 2293 . At that point , Kirk proclaimed the Klingons were untrustworthy and favored simply allowing them to die , due to his old grief and rage over their role in the death of his son . ( ) Memorable quotes . " " Every time we have dealings with Starfleet , I get nervous . We are dealing with something that . . . could be perverted into a dreadful weapon . Remember that overgrown Boy Scout you used to hang around with ? That ' s exactly the kind of man . . . " " " " Listen , kiddo , Jim Kirk was many things , but he was " never " a Boy Scout ! " " " " I ' ve tried to tell you before , scientists have " always " been pawns of the military ! " " " " Where ' s Dr . Marcus ? " " " I ' m " Dr . Marcus ! " " " " You knew enough to tell Saavik that how we face death is as least as important as how we face life . " " " " Just words . " " " " But good words . That ' s where ideas begin . Maybe you should listen to them . I was wrong about you . . . and I ' m sorry . " " " " Is that what you came here to say ? " " " " Mainly . And also that I ' m . . . proud , very proud . . . to be your son . " " " " This is where the fun begins , Saavik . " " " " Just like your father – " so " Human . " " " " Hello , sir . It ' s David . " " " " I ' m sorry I ' m late . " " " " It ' s OK ; I should ' ve known you ' d come . But Saavik ' s right . This planet " is " unstable ; it ' s going to destroy itself in a matter of hours . " " " " David , what went wrong ? " " " I went wrong . " " " " I don ' t understand . " " " " I ' m sorry , sir . Just don ' t surrender . Genesis doesn ' t work . I can ' t believe they ' d kill us for it . " " Appendices . Background information . David Marcus was played by Merritt Butrick . When casting Butrick in the part , director Nicholas Meyer found the actor ' s appearance to be acceptable . " " He not only had to be Kirk ' s son , he had to be Carol ' s son , " " Meyer recalled , " " so on a physical level I think what I liked was that his hair was the same color as hers but it was curly like Bill ' s , so I thought , ' Well , that ' s plausible . " " ( ; ) Butrick himself liked that the storyline of " Star Trek II " focused on the characters but he also felt somewhat " odd " about playing David because doing so involved interacting with voices he was highly familiar with , having been " raised on " Star Trek " . " ( " The Making of the Trek Films " , 3rd ed . , p . 171 ) Regarding the artistic consideration that went into writing Marcus ' death , Leonard Nimoy felt that " " The death of David Marcus has its roots in all the classic tragic forms . It is the vengeance of fate wreaked upon the flawed person who created the problem . David is the character who much pay the price for whatever wrongs he has done , and for whatever pain and suffering he has inflicted – intentionally or not – on others . He put the Genesis device into operation prematurely . " " Nimoy continued , " " My major concern regarding David ' s death was the accuracy of the scientific aspect . I thought we had better tread carefully there , because , in effect , we were saying that scientists can ' t always be depended upon to be & ndsah ; you should pardon the expression – " logical " . We were accusing a scientist of prematurely finishing an experiment with which he had become impatient . I checked with some very important scientists on this subject , and they told me it happens all the time . So we went ahead with that plot development , which I felt was a very valuable and well - placed story point . " " ( " " # 106 , , p . 53 ) Apocrypha . " " gives his full name as David James Marcus . According to the novelization of by Vonda N . McIntyre , Lt . Saavik is supposed to have had a short relationship with David Marcus . " The Mirror Universe Saga " establishes that , in the mirror universe , David Marcus was believed killed by , but he had survived and was leading the rebellion against the Terran Empire on Earth . In the mirror universe story " The Sorrows of Empire " ( which takes place in a different continuity from " The Mirror Universe Saga " ) , Carol Marcus thanks Emperor for killing as she had lived in fear for years of what he would have done had he known about David ' s existence . Spock tells Carol that she was right to fear Kirk , as he would have killed them both . The " " novella " A Less Perfect Union " – set in an alternate quantum reality where Earth cut off contact with the rest of the galaxy due to the success of Terra Prime in 2155 – establishes that David , as well as his mother Carol , ( who in this universe , had married Kirk ) , had been killed aboard an UESPA starship , en route to a conference on Vulcan , their ship being destroyed by a Vulcan ship near the United Earth / Interstellar Coalition border , which embittered Kirk for years toward Vulcans . Additionally , David is a main character in " The Chimes at Midnight " , set in the alternate timeline from where Spock died as a child in 2237 . In this timeline , because there is no Spock for Kirk to come rescue , David and Saavik are taken aboard Kruge ' s Bird - of - Prey and David is subsequently tortured for information about Genesis before he and Saavik are rescued by the " Enterprise " crew , although Kirk sacrifices his life and destroys the " Enterprise " to save everyone else . David and Saavik cultivate a relationship and , as relations between the Romulan Star Empire and the Federation deteriorate , David remains on Romulus to live with Saavik .