In the Star Trek TOS episode 28, "The City on the Edge of Forever", we find that McCoy's drug-fueled tear through the past caused serious and far-reaching effects on the space-time continuum; to wit, the delay of the US' entry in World War II, its loss to Nazi Germany, having developed the atomic bomb before the US, which eventually prevented the Enterprise and the Federation from ever existing. The crux, Edith Keeler, a pacifist, and Kirk's love interest of the week, didn't die due to McCoy's intervention.

But did she really have to die?

For the moment, let's put aside the dramatic effect of Kirk having to make a sacrifice and lose his true love to allow history's normal course to be restored. Let's also put aside the Vulcan logical argument that the needs of the many outweigh the needs of the few, or the one. Fine, but, Edith Keeler's death is like using an ICBM to destroy a mosquito. All that really needed to happen was to prevent her from starting her pacifist movement at that time. It could have been delayed until after World War II, or longer.

So, following that reasoning, why didn't they just take her back through the Guardian's gate to their present? The Guardian didn't seem to have any issue with people passing through the gate per se, just the adverse effects of changing the timeline. Had Edith disappeared at the moment of her death, she would have been removed from the timeline as in the original course, but she would have been able to do good humanitarian work in 23rd century instead of the 20th. In Star Trek IV: The Voyage Home, someone from the Enterprise's past is brought forward in time with them, and for good reason. No sacrifice, no death, no terrible ripple effects. And, Edith still makes a sacrifice: she must give up her cause at that place and time to stay alive. Live today, so you can fight tomorrow.

So, if we put aside the dramatic effect, the logic of "sacrifice for the greater good", why couldn't Edith Keeler have been removed from the timeline without killing her?

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    Because her death would have had wider consequences than just removing her from the timeline. What about the driver and the witnesses? What about the time/effort/energy wasted in trying to locate her if she just went missing?
    – Valorum
    Commented Dec 29, 2015 at 23:15
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    What if she screwed up the 23rd century? Couldn't let that happen. Edith had to be stopped at all costs. Pacifists are bad for the defense of the Galaxy business. Commented Dec 30, 2015 at 3:34
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    "All that really needed to happen was to prevent her from starting her pacifist movement at that time." - but would that return the Enterprise crew's timeline, or would it result in a yet another timeline in which they didn't exist? All the crew knows for sure is that in the timeline in which the Enterprise and Federation definitely exist, Edith Keeler dies.
    – user22478
    Commented Jan 11, 2016 at 20:51
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    Yes. She had to die. Spock said so.
    – Valorum
    Commented Dec 31, 2016 at 20:58
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    In my headcanon, Edith Keeler's survival is the event that leads to the formation of the Terrain Empire in the mirror universe.
    – Graham Lee
    Commented Feb 22, 2018 at 12:59

9 Answers 9


In the following remember that the entire Federation had disappeared, these people were in a very serious quandary, Captain Kirk even instructed them to wait and each try to correct the time stream in turn.

Lt. Uhura poignantly says: At least a chance for happiness sir.

  1. "prevent her from starting her pacifist movement at that time" How? Short of keeping an eye on her 24/7 for the rest of her life there is no guarantee she wont do it. (Who's to say how long WWII will last in this altered timestream)
  2. Using the Guardian is not precise they had to go in before Dr. McCoy, even then it was by days.
  3. Most important, in the Enterprise timeline Edith Keeler dies. A single disturbance will have far reaching and unpredictable consequences.

Just because I want to see it!
Guardian of Forever

  • I know what you are thinking Tomorrow is Yesterday. To that I say, the slingshot was a deliberate move by the Enterprise (supposed to happen?) whereas the Guardian event was an accident. Commented Dec 29, 2015 at 23:25
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    I'm disappointed the solution wasn't yank her out of her time to your time.
    – Joshua
    Commented Jan 20, 2018 at 3:05

SPOCK: I was recording images at the time McCoy left. A rather barbaric period in your American history. I believe I can approximate just when to jump. Perhaps within a month of the correct time. A week, if we're fortunate.

KIRK: Make sure we arrive before McCoy got there. It's vital we stop him before he does whatever it was that changed all history. Guardian, if we are successful

GUARDIAN: Then you will be returned. It will be as though none of you had gone.

So they couldn't take her back with them because the GoF said they'd be returned only if they succeeded in stopping McCoy...which meant stopping him from saving her life.


I think there are three reasons why Edith Keeler had to die. One is the purely practical "real world" script writer's reason. It was suggested that Kirk, et al take Edith back through the Guardian of Forever. If she did go, Kirk, as a character, loving Edith as much as he did, would probably give up command and settle down with her, so the producers would have to find another Captain. Edith wasn't really a 'girl of the week' type character (like say, Shana on Triskelion).

The second possible reason is that as we now understand time, events probably cannot be altered in reality, were time travel actually possible. What Spock saw with his 'stone knives and bear skins' computer (Nazis winning, etc) was a temporary glitch in the time line. The time line got restored because that's how time works. Edith had to die, because that's what originally happened.

The third possible reason would be that if the time line can actually be altered by time travellers, and if she were not killed - if Kirk tried to take her back to the 23rd century- then, as someone mentioned, she would be considered disappeared and it might set off a completely different (and perhaps worse) outcome, since death comes with different consequences than a disappearence. So, this explains Kirk's anguish as he realized that the only way to set things right was to have Edith die.

  • Agree completely. Also, if Kirk did retire to settle down with Edith in the 23rd century, that would de facto alter the timeline for everything beyond this episode (or the point where he retired) as the Enterprise would no longer have Kirk at the helm as we knew him to be. Even if he chose to remain in the service, having someone like that to get home to would almost certainly have an effect on his command decisions and his willingness to take risks.
    – Steve-O
    Commented Dec 31, 2016 at 21:35
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    "events probably cannot be altered in reality" - while time travel is not always completely consistent across Star Trek, I think we can safely exclude that option based upon various other episodes. Also, it seems rather far-fetched to me that "time" would somehow semi-automatically correct itself by placing people in such a way that certain "events" happen. That sounds quite a bit like the premise of Final Destination, but is not really believable. Commented Feb 22, 2018 at 10:08

Yes, because her life is a Focus Point in Time. The core of this episode is explained by Edith being a Focus Point in Time, which seems to be something where it's so obvious that a person has to die, that no one questions it (even if other things are less sure, as we will see below).

As a side note, it's a common enough trope also within the Star Trek universe that one specific thing has to happen no matter what, else the consequences would be dire (such as Gabriel Bell, and no one else, leading the riots in DS9's "Past Tense").

In the beginning of the episode, it's established that finding McCoy will be almost impossible, even if they hit the right time period. Kirk is fully aware of that and even asks Scotty to also attempt jumping into the past if Kirk fails (and good luck with that, since Spock took his tricorder with him, which enabled him to jump to the right time in the first place!):

UHURA: Captain, it seems impossible. Even if you were able to find the right date...
SCOTT: Then even finding McCoy would be a miracle.
SPOCK: There is no alternative.
KIRK: Scotty, when you think you've waited long enough. Each of you will have to try it. Even if you fail, at least you'll be alive in some past world somewhere.

And yet, Kirk and Spock manage to conveniently jump to the right time and right place, and quickly meet Edith Keeler. And so does McCoy, just a bit later.
But how?

The answer is that she is a focus point which drew all of them to her, as Spock later finds out.

KIRK: We know her future. Within six years from now, she'll become very important. Nationally famous.
SPOCK: Or Captain, Edith Keeler will die this year. I saw her obituary. Some sort of traffic accident.
KIRK: You must be mistaken. They both can't be true.
SPOCK: Captain, Edith Keeler is the focal point in time we've been looking for, the point that both we and Doctor McCoy have been drawn to.
KIRK: She has two possible futures then, and depending on whether she lives or dies, all of history will be changed.

This explanation is enough for Kirk and Spock to assume that this is a black and white situation: Either she lives or she dies, there is no middle ground. They seem to infer this from the "focal point" theory, which, in turn, seems to be the result of Spock's investigations. And that's all the explanation we get, from here on out, it's only about her living or dying, nothing else.

At this point, they don't know yet if Edith is supposed to survive or to die, but Spock finds out shortly after:

SPOCK: And all this because McCoy came back and somehow kept her from dying in a street accident as she was meant to. We must stop him, Jim.
KIRK: How did she die? What day?
SPOCK: We can estimate general happenings from these images, but I can't trace down precise actions at exact moments, Captain. I'm sorry.
KIRK: Spock, I believe I'm in love with Edith Keeler.
SPOCK: Jim, Edith Keeler must die.

Interestingly, neither Kirk nor Spock question at this point that she has to die, even though the facts seem to be fuzzy enough on how she had to die (and thus questioning the whole "we have to prevent McCoy from saving her" plot, begging the question why they couldn't just kill her and wait for the Guardian to bring them back to the present).

This comes up after Spock has told us multiple times that Keeler died in some kind of traffic accident. Yet, after Kirk caught her when she tumbled down a flight of stairs. this happens:

SPOCK: I must point out that when she stumbled, she might have died right there, had you not caught her.
KIRK: It's not yet time. McCoy isn't here.
SPOCK: We're not that sure of our facts. Who's to say when the exact time will come? Save her, do as your heart tells you to do, and millions will die who did not die before.


tl;dr - possibly not, but it's the only way to be sure.

In the original timeline, she dies after being hit by a car, and has relatively little effect on time.

In the second timeline, after McCoy returns, she is not hit by a car, and her pacifist ideals gain popularity, resulting in America not entering the war. Now, as others have said, for the US to not enter the war after Pearl Harbor is a hard thing to believe, but in this new timeline, with her voice already being a major influence of calm and peace, there's a chance that Japan might have decided the attack wasn't necessary. But that's sheer guesswork.

In the third timeline, after Kirk and Spock go back, McCoy is stopped from saving Edith, she dies in the accident, and the future is restored. Considering that in that version of the incident, she crosses the street because she sees Kirk and McCoy, and walks to join them, they have still technically changed time, in that the reason for the accident has changed. Or, if you want to apply a bootstrap paradox to the proceedings, they cause the accident all along.

The question is, considering how good Kirk is at convincing people of things, could he have given a speech to Edith that got her to realize that, say, sometimes violence is required against a force so horrific that they won't listen to anything else? She could have lived on her life helping people in a small missions a few stores down from Floyd's Barber Shop, and never rose to national prominence.

The effective word there is "could".

There's too many variables and permutations in a situation like that, and they'd never have the opportunity to tweak things if she changed her mind again about speaking up. So to guarantee the preservation of the timeline, she needed to expire as she originally did.


Unless the WWII of the Star Trek reality was substantially from our own Edith Keeler did not have to die.

"From the start of the war until the late fall of 1941, the German 'lightning war' had marched from one victory to another, subjugating most of Europe. During this period, the Germans needed no wonder weapons. After the Soviet counterattack, Pearl Harbor, and the German declaration of war against the United States, the war had become one of attrition. For the first time, German Army Ordnance asked its scientists when it could expect nuclear weapons." (NOVA: Nazis and the bomb)

Because Germany only started looking at atom bombs in 1942 they were three years behind the US program which had started in 1939 and they never caught up--they only got to an early part the 1942 stage of Manhattan project in 1945. From what we can put together the best Germany could have produced in 1946 was a conventionally powered "dirty bomb" : "At best this would have been far less destructive than the atomic bombs dropped on Japan. Rather it is an example of scientists trying to make any sort of weapon they could in order to help stave off defeat." (NOVA; Nazis and the Bomb)

Another problem is the V2. In OTL when Hitler was first shown the plans for the V2 in late 1941 he was dismissive of the V2 as essentially an artillery shell with a longer range and much higher cost (Irons, Roy. Hitler's terror weapons: The price of vengeance. p. 181.) It was not until 1944 with German moral waning in the face of defeat after defeat that Hitler decided on building the V2.

In anything resembling OTL it is a catch-22 situation: a more successful Nazi Germany thanks to less US involvement would mean delaying both the German A-bomb (not really viable until 1948 under the best of conditions) and the V2 to carry it. So delaying US involvement in WWII essentially delays the very weapons that supposedly let Germany win the war!

Also the V2 simply didn't have the ability to carry an A-bomb...that is why Stalin put so many resources into duplicating the Superfortress instead of simply copying the V2 and slapping an a-bomb on top of it.

IMHO, the only thing that makes any sense assuming the Edith Keller dies TTL is anything like OTL is in the she lives timeline Edith Keller tries to meet with Hitler ala Neville Chamberlain and this allows Hitler to be killed putting a more competent megalomaniac in power. This new leader of Nazi Germany is far more visionary then Hitler and puts far more resources into the A-bomb and V2 projects having them completed much earlier then in OTL. November 8, 1939 IMHO seems most likely date for this being one of the closest assassination attempts on Hitler.

Extend the speech (perhaps to placate Edith Keeler who might be in the audience) and bye bye Hitler.

Remember that Edith Keeler is the key to all this so we can't be going all ASB to make things fit; so more on track German A-bomb and V2 programs must somehow relate back to her rather then simply the results of her actions.

By itself a less involved US means a more successful Germany which means less investment in the A-bomb and V2 programs not more delaying them even further than in OTL. Even with both the US and USSR in the war the German A-bomb program was only at 1942 stage of OTL's better funded Manhattan Project in 1945 and it was planned to stave off defeat.

SPOCK: She was right, but at the wrong time. With the A-bomb, and with their V2 rockets to carry them, Germany captured the world.

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    I don't recall any mention of the A-bomb or the V2 being key to Germany winning in the timeline in which Edith died. Only that the US staying out of it (or getting involved too late) allowed Germany to win.
    – JRE
    Commented Jun 1, 2018 at 16:41
  • So, in short, you agree with the OP's thought that removing Edith Keeler from the timeline would have been adequate to prevent the change in the timeline that our friends from the future caused? This seems to be more an attempt to explain how a live Edith Keeler could possibly have made the impact stated - delaying the US's entry in the war, resulting in Germany developing nuclear weapons and conquering the world. One suspects that the writers were not necessarily working that hard at developing a realistic alternate history.
    – RDFozz
    Commented Jun 1, 2018 at 16:48
  • If the US is delayed in entering the war, Britain falls. Britain was having success with atomic development before 1941. Then all the research there becomes available to the Axis powers.
    – JohnP
    Commented Jun 1, 2018 at 17:15
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    @JRE - From the memory alpha - "She later went on to found a pacifist movement whose influence on President Roosevelt delayed the United States' entry into World War II. As the peace negotiations dragged on, Adolf Hitler and Nazi Germany had time to complete their heavy water experiments, allowing them to develop the atomic bomb first, with which Germany conquered the world" - Also confirmed in a transcript
    – JohnP
    Commented Jun 1, 2018 at 17:23
  • The problem with the pacifist movement was that until Dec 7, 1941 the US was effectively dead set with getting directly involved in the Once Japan bombed Pearl Harbor the whole pacifist movement would have gone down faster then the Arizona. Commented Sep 19, 2018 at 13:04

One of the replies above may address this, but.... It almost seems she was destined to die, no matter what happened. At one point she stumbles at the top of a flight of stairs, only to have Kirk catch her before she falls. She may have died had she fallen then. Its possible that even if she were taken into the future, something would have happened to kill her anyway, if it was actually destined that she should die (reminds me a little of the plot of the game "Life is Strange", that has a similar plot point revolving around the seeming inevitable death of a person, and how preventing that could result in disastrous consequences).


Those of you who are worried about the search for Edith Keeler setting off effects are forgetting 2 things.

First, in the episode in which the Enterprise goes back in time and is spotted by an Air Force pilot whom they opt not to bring back with them the standard given for the decision was whether or not the pilot would accomplish something of significance. By that standard Edith Keeler simply needed to not lead the pacifist movement that delayed the US entry into WWII.

Second, if were going to assume that a relatively small thing like whether she died or simply disappeared had much bearring then we must consider that had it not been for our heroes putting her in that place and time Keeler would not have been hit by the car. For that matter she wouldnt have stumbled on the stairway either.

No, the questions of significance are,

  1. Could Keeler have returned with them through a window in time created by the portal? Or was it necessary that someone actually go through the physical gate before they could return through it?

  2. Could Kirk have used one of his time travel tricks to return for her once he had recovered the Enterprise?

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    If you think you have a more relevant question to ask about this episode, you should post it as a new question, rather than as an answer to an old one. You could also include a link to this question in your new question, to show that it was inspired by this thread. Commented Jun 14, 2021 at 1:41

Edith Keeler needed to die as far as observers go. In a general time travel rules sense there are always workarounds and then the answer is NO.

Consider the movie Millennium (1989). People from the future rescue the victims of plane crashes and replace the bodies. History still records they died but in reality they live in the future.

But Kirk did not have the means to do that. He has to do the best he can with what he has available. And thus his only choice is to let time proceed naturally.

Does that stop some future time traveler from replacing Edith with a duplicate to die in her place? No. It could happen and there would be no paradox either way.

Starfleet's prime directive applied to time while perhaps not a policy in Kirk's time as it was in TNG and later is to not interfere and this sense of ethics would have still guided Kirk despite the exaggerated caricature reputation he has for rule breaking. Kirk has no more right to save Edith than he has to go kill Hitler.

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