Meaning of 残す, 結びつく and ては

Question

First, a bit of context: there is a knight who grew up with the princess, and they were very close; in the end they killed each other (which is said in the prelude, and then the story kinda goes back).

The princess then is shown as ruthless, executing people deemed as rebels and their families with cruelty, like first killing the young son just to make the parents suffer.

Meanwhile the knight is shown as blind and is treated as a rebel by her former comrades.

In the scene, the knight is figthing with her former teacher, and the point of view is another character.

This is the sentence I'm not sure about:

「先生に勝つには、相打ちしかない。だが私はまだ死ねない。陛下を残しては死ねないのです」

（陛下……？）

一瞬、リーベルヴァイン王の顔が浮かぶ。残虐な処刑と、あの無慈悲な高笑い。しかし、それが「陛下を残しては」という今の台詞と結びつかない。

I read 陛下を残しては死ねないのです in two possible ways:

• "If Her Majesty is still alive, I can't die" (with this meaning of ては), and since the knight is a rebel and the princess a tyrant, it'd make sense if the first wanted to stop the second; but I don't understand how それが「陛下を残しては」という今の台詞と結びつかない follows: I think it means "That [the cruel executions and loud laughters] doesn't fit the sentence 'If Her Majesty is still alive'", which doesn't really follows.

• "I can't die leaving Her Majesty behind", which - if 残す as "to leave behind" as a meaning of abandoning - would make sense with the following part, since the point of view character wouldn't understand why the girl would be reluctant to abandon such a tyrant; in this case, ては sounds to me like an "and" ("I can't leave her behind and die"), but I'm not sure if 残す can have that implication, nor if it's right to read ては that way.

Despite the princess (now ruler) being a girl, リーベルヴァイン王 refers to her, since the point of view character saw her doing those executions, and thought about her "あれが、リーベルヴァイン王".

I think the knight's sentence should make sense given the background (knight and princess know each other since they were child, and they were close), but the narrator - not knowing their background - sees a mismatch beetwen the tyrant she knows and what the knight said; I think the second meaning is the right one ("I can't die leaving Her Majesty behind"), but I'm not sure and I am unsure about 残す and ては as said above.

The quote is from 僕の愛したジークフリーデ vol. 1, by Matsuyama Takeshi.

Answer 1

You might find the sentence easier to understand if は is moved to a different position, like this.

［陛下を残して死ぬこと］はできないのです。

What the knight says she can’t do is dying leaving Her Majesty behind. Here, て can be understood as indicating the attendant circumstances under which she dies. She’s basically saying she needs to be alive for Her Majesty. Nobody knows why at this point, including the narrator. But it doesn’t seem to matter. I think the narrator just finds it hard to connect the knight’s reverential language towards the queen with the cruel and merciless person she knows.

Answer 2

In my opinion, the first interpretation is possible, but is unlikely. It is possible if we assume:

• 残す to mean "to leave Her Majesty alive"
• the knight's impression of the queen has completely soured at this point in time, to the point that the knight feels compelled to kill her, and that the knight still calling her 陛下 is just a habit or a type of 未練
• the narrator somehow perceives the queen to be stronger than the knight due to them having witnessed the queen's actions

then, the narrator might indeed find the idea of the knight leaving the queen alive to be a mismatch. However, I think these assumptions are a bit of a stretch given the context, and also because 残す does not typically mean "to leave someone alive" unless in a specific context like e.g. 他の人は殺したが、あの人は残した where it makes sense to use 残す in favor of 活かす or 逃す. Instead, 残す does typically mean "to leave someone behind", so I believe the second interpretation is correct.

As for the phrase itself, it is not different from other phrases in this (situation-て)(potential-ない) form. However 残す may have two meanings which can change the interpretation of the sentence slightly. 残す can in general be interpreted as "to leave someone behind (in the current undesirable situation e.g. alone, under the care of untrustworthy people, in a battle etc.)", or "to leave someone behind (in this world)". The は that follows adds an optional comparative emphasis here: in the former meaning of 残す, the は emphasizes that the speaker is willing to die if the well-being of the queen was no longer a concern, or that the speaker is going to ensure/confirm her well-being no matter what it takes. In the latter meaning, the word 残す is more emotionally loaded (which makes sense given the closeness of the knight and the queen), and the speaker is emphasizing that they are essentially not willing to die.

In the current context, the first meaning of 残す may be something like "to leave the queen in the state of being a tyrant", and the speaker is expressing their resolve to ensure this changes. The second meaning of 残す will be what you suggested: the knight is unwilling to do die because they still have the queen to live for. Notice that both these cases belong to the second interpretation where the knight's impression of the queen has not completely soured.