Amy has been forced to become an adult baby by her sicko aunty and kept a prisoner in a hidden nursery in her aunty's house.

It has been well over 24 hours since her aunty has come in to take care of her and she is starting to panic. What if her aunty is not coming back? She cries and cries
Then she hears a door open and someone enter. But it is not her aunty. It is a stranger from across the road who had heard the crying when she was out for a walk.
The stranger's name is Belle and she is very concerned about little Amy being left alone and consoles her with big hugs and cuddles.
Amy explains she is really an adult who came to visit her aunty for just a week some months ago but has been forced to be a baby.

She fully expects Belle to release her from Aunty's torment.

Belle's demeanour changes and she tells Amy a harshly not to be silly, of course she is a baby.
Belle wants to care for this baby she has found though and realising Amy has not had anything to drink for a whole day bodily lifts her out of the cot and carries her on her hip to an arm chair where she feeds her a much needed bottle of lovely warm milk.
The next most important task is to change Amy's absolutely saturated diaper. It had not been changed in over a day.
All the time Amy keeps insisting to the lady that she is really and adult but Belle is adamant she is not.
Belle makes certain Amy is breast fed, much to Amy's disgust, spoon fed and has her diaper changed on a change table. There is a great POV diaper change scene from Amy's perspective.
When she is left alone for a short time Amy peeks in some drawers and finds her real adult clothes. Now she is almost sure she should not be kept catpive as a baby. Bell caches her putting on her grown up bra and other clothes and is furious. She drags her over her knee to administer a good, firm OTK spanking. Finally Amy drops off to sleep while being breast fed and Belle dresses her fast asleep baby in a snug footed sleeper and lifts her into the cot.
Amy stirs a short whole later, realises where she is and starts to cry because she is sure, well almost sure, that she is really an adult.