Potion disaster

One Mistake is all it takes.
One Mistake causes a restart.
One mistake is all it took.
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When one enemy turns into a Friend,
With one friend is acting weird,
Which friend is actually right,
Where one friend isn't as true as it seems,
With a friend or three dissapearing,
When one friend turns into a.... Child?
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ALSO! I'M NOT GREAT AT ENGLISH!! So if I make mistakes like forgetting certain letters either inform or ignore. Don't be rude about it.
Drarry fic.
Warning!
This fic will include topics such as neglect and abuse (mental and physical) manipulation and mild torture.
also there won't be any romantic feelings between Harry and Draco while Harry is a child.