¿Why people die taking the drug and other ones survive?
How can anyone surviving is a side effect, this definitely has some back story which apparently Haibara knows and hasn't told shinichi yet.
I agree with you
Haibara was thinking to her self " But what they really wanted me to make .... was another drug" File 948 page 4
She never addressed what was the different drug they wanted, neither did she tell Conan about it (Conan isn't the only secret keeper here)
We originally thought that Haibara was recreating her parents drug from the burnt data she got when she started working for them, but now haibara is claiming they didn't want her to do the same drug but another one.
Why ? was Silver Bullet not done ? not good enough ? change of purpose ? they ran out of Silver bullet ?
Who took APTX 4869 and who took Silver bullet, when were each one of them made ?
Those are all unanswered questions we have gosho has yet to answer
I dont have a theory here, but its just an idea I had for a FanFiction Story .... ( Please Don't judge me for that ) I will still write this fan fiction
Here is the idea
Elena and Atsushi worked on the drug with stages, One stage killed people with no trace and another stage reached a shrinking result, they decided to hide they shrinking drug, and hid the drug they made somewhere mysterious ( maybe with Mary or a British/Japanese friend )
The Organization used the killing drug as much as they wished
However, Someone heard the miyano's deciding to hide some new results, so they rated them out, Elena was aware there life was in danger because of her and her husbands actions, so she recorded the tapes for her girls ( assuming maybe akemi got some tapes too ) She was sure she wasn't going to risk her children life, although leaving them with the Bo is a risk it self, she still had hope that her kids wont be killed, and had thoughts that her kids will be forced to work for them, at least one of them ( assuming Shiho somehow was an abnormal smart child, maybe Talked or walked early )
Somehow Vermouth got a hold of that drug by mistake and turned younger - Or she got a previous stage that stopped aging ( Assuming Vermouth was there test subject for a while - explains why she hates them )
The Miyano Parents were indeed killed for their mysterious actions, hiding the results of the future drug Silver Bullet ( No one finds it yet )
Shiho was sent to the US to study, and came back to get the data left behind from her parents, she reached the killing stage as The BO wished
Here we go - Main Story Idea
Akemi had been with her parents and knew where the shrinking drug is, she went ahead and found it, and started sneakily slipping it into shiho's lab coat to see what will happen, as shiho seemed to have told her sister everything. Shiho discovered the mice shrinking and thought it was a just a side effect, Akemi decided to keep it that way and once again, slips another drug into shiho's coat and shiho ended up putting it with the batch Gin took and used on Shinichi, who was lucky enough to get the shrinking drug instead of the killing drug
Akemi plans the escape from the BO plan, and puts another piece in shiho coat, fearing she would get killed, shiho might decide to commit suicide, and that happens,Akemi is killed, shiho tried to kill herself with the drug she made, however she takes the shrinking drug unknowingly and turns to a child - later known as Haibara Ai.
Mary might have gotten one of those from when Akemi slipped a few of the pills in shiho's coat ( assuming shiho always kept a few in her pocket originally, which made it easy for akemi to switch them secretly.
Of corse, this does not explain everything, I am still thinking of how the story will go, and will not write it until a few things are explained and confirmed by gosho and the mange ( like Elena and Mary being sister for example )
Any thoughts ?