# Killing Conjoined Twins using Death Note

There are Mr. A and Mr. B. They are conjoined twins who each has their own set of organs except for the heart. I write the name of Mr. A while imagining his face, with the cause of death being falling from the top of Tokyo Tower head first. Let's say the difference in height between the two is less than 1 cm. Will Mr. B also die?

According to How to Use: XXVI, item 2:

Even though only one name is written in the Death Note, if it influences and causes other humans that are not written in it to die, the victim's cause of death will be a heart attack.

However, a heart attack will also kill Mr. B.

Additionally, How to Use: X, item 2 stated:

Whether the cause of the individual's death is either a suicide or accident, if the death leads to the death of more than the intended, the person will simply die of a heart attack. This is to ensure that other lives are not influenced.

This question is a bit different than the one proposed as possible duplicate. In the proposed question, the death of the pilot or the surgeon doesn't necessarily means that the people in the plane or the one in the surgery will 100% die. There is a delay before they actually die. Surgery is rarely done by only one doctor. It usually is done by a team of doctors, so the other doctors can still save the patient. Flying a plane is also the same. There is also the co-pilot. In the case of my question, killing Mr. A is the same as killing Mr. B since they share the same heart with no delay whatsoever to save Mr. B.

Even though only one name is written in the Death Note, if it influences and causes other humans that are not written in it to die, the victim's cause of death will be a heart attack.

Does rule XXVI not answer your question? Mathematically speaking you could rewrite it as follows.

Causes others to die => (Cause = Heart-attack).

Here you could see that the heart attack would be logically implied as the cause of death if others are influenced, regardless whether they take others with them. Therefore they would both die. Mr. B would also be killed. Remember that this rule does not say that if you would cause another human to die, that you would stay alive. It only says that the cause changes to a heart attack, which in this case would kill both, so the death of the other would be unavoidable in this case.

If this would not have been true, Light would have been able to make himself completely immune to the Death Note, even making it impossible for Ryuk to kill him. Light could have implanted a bomb inside a few people, that would all be triggered when either his heart or their heart stopped beating. He would repeat this over different groups of people. By doing so, Ryuk would be rendered unable to kill Light as it would be impossible to kill any of those with a bomb implanted, as it would kill the others and he would not be able to kill Light as it would kill all of them. This would make Light immune to the Death Note, which I found very unlikely to be true, because it would completely contradict the first and most fundamental rule of the Death Note namely

The human whose name is written in this note shall die.

• It contradicts How to Use X:2. I've added that to the question. Commented May 27, 2015 at 8:38
• @SakuraiTomoko It does not contradict. rule X:2 says that the victim will die of a heart attack and that is exactly what will happen. Like I said in my answer, rule X:2 does not say "If a person is influenced, the victim will stay alive", the victim will die of a heart attack and there is just no other way for B to stay alive, but that does not contradict any of the rules. A will die of a heart attack as mentioned in both rule XXVI and X (taking B with him) Commented May 27, 2015 at 8:48
• It contradicts the second sentence of the rule. This is to ensure that other lives are not influenced. Commented May 27, 2015 at 9:30
• @SakuraiTomoko That is the reasoning behind the rule, but the actual rule is not contradicted. The reasoning is that a heart-attack would not influence others, but this is obviously not true in many cases. Imagine another case, where we want to kill a pilot in mid flight. This would make the plane crash and kill lots of people. If at that specific time, the pilot could not be killed, it would contradict one of the most fundamental rules namely every person whose name is written down will die. Commented May 27, 2015 at 9:51
• Wouldn't the bombs just malfunction if Light dies from a heart attack?
– Gao
Commented May 27, 2015 at 11:26

Although Peter Raeves has given quite a good explanation as to why they will simply both die, there is also the possibility that rule XXVI does imply that no other people will die because of the person's death. In practice, this would be a hard rule to follow (pilots dying whilst flying, doctors dying whilst operating, a conjoined twin...), but for the world of fiction, it of course wouldn't.

You can always think of a scenario where no other people will die. The bomb scenario in Peter's answer, for example, can be debunked with simple technology malfunction. Every time Ryuk writes down a name, there is the extreme coincidence that the bomb on that person disables for what seems to be no reason.

For the conjoined twins, they can have a heart attack, yes. However, you can be revived after this. So people try to revive them both, but only Mr. B gets to survive, and the other dies.

Every thinkable scenario can be debunked in the world of fiction :)

• Are you saying that the Death Note would take A, but magically create a scenario where B would be brought back to life, without bringing A back? If that were the truth, then I guess we cannot solve this discussion without further proof. Commented May 27, 2015 at 14:44
• I don't claim for this to be the truth. I thought I'd just bring up my thought. We do indeed need some more information. Commented May 27, 2015 at 15:06