Several weeks after the Flynn –Fletcher family moved to the kingdom, Isabella was starting to spend more time than ever outside of the palace walls. Every day she would find a reason to visit the village, just to join Phineas and Ferb in their activities. She also learnt more about the other children in the kingdom; like that the girls had created a group called the 'Fireside Girls'. She longed to join the group, but wasn't so sure her father, the king, would let her. He was quite protective of his literal princess, and once he found out what the Fireside Girls do, he would throw a fit.
One day, about a month and a half after the family arrived, Isabella couldn't find a reason to visit the village – her parents wanted her to stay inside for once. She had protested, wanting to see Phineas and her other friends, but she couldn't persuade them. She spent the day moping in her room, daydreaming about the handsome boy who became the one she loved in such a short time.
Whilst the princess spent her day in the castle, Phineas spent the whole day worrying; thoughts of something bad happening to the beauty of his dreams. Yes, Phineas had fallen in love with the princess, but knew that it was inappropriate. He was a commoner, and she was a princess. It would never be allowed.
Of course he had noticed the dreamy looks that she gave him though – who didn't? – But he chose not to say anything, even though it only intensified his feeling for her. The forbidden love; it makes things seem more dangerous and exciting, like an adventure, and Phineas loved adventures.
On this one day though – the first day he had spent apart from her in more than a month – he was deeply worried, almost pained, about her. Ferb reassured him that she was probably just spending the day with her family, and even though it was an extremely logical explanation, it didn't settle the worry or the butterflies fluttering in his stomach.
That night, Phineas had his first nightmare since he was little. He woke up drenched in his sweat, clammy, and shaking. He had dreamed something had hurt the princess, and even after comfort from his brother, sister and pet platypus, he still couldn't sleep.
Isabella couldn't sleep either, and after being in bed for three hours, with sleep eluding her, she decided to take a walk around the palace grounds.
The next morning, the princess was allowed to visit the village once again. It was an extremely tired Phineas and Isabella that greeted each other the next morning, but just the sight of each other made them smile, and become more alert.
That night, the two were able to sleep peacefully, dreams filled with happy thoughts of a future with their true loves.