Gloria figured that she was so hard to notice as a fly that this was a great opportunity to go tour the rest of the Transformation Resort without worrying about where she was allowed to go. So she started flying around, first finding the Age Wing. Growing older or being young again sounded mildly interesting to Gloria, but she didn't know how to handle it as a fly. She didn't want to age herself beyond a fly's lifespan and then simply drop dead, and nor did she want to become a maggot or even a larva. So she moved on.
The Gender Wing was interesting. Maybe be a male fly for a while, and find a female fly to impregnate? Conceptually it sounded interesting, but Gloria had several reasons for not being sexually attracted to female flies. Maybe it would change once she transformed, but as of now she wasn't interested.
The Size Wing, on the other hand, had potential. She saw humans ranging from a foot or so tall to ten or fifteen feet tall, all hanging around an otherwise normal beach resort. It was kind of cool, and certainly no one noticed something so insignificant as a fly buzzing around. Still, Gloria took care to stay away from humans to avoid being swatted.
The centerpiece of the Size Wing was the tunnel room. Although the Size Wing gave guests several different ways to change their size, the tunnel room was one of the most popular. You simply walked through one door corresponding to your size, and walked out another door corresponding to the size you wanted to be, with lots of connecting tunnels in between. So if you were a person who wanted to shrink yourself, you would go into a normal-sized human door, and leave through a tiny door. Gloria noticed that some of the doors were almost invisible to the naked eye, while some were as tall as buildings. There was room for plenty of fun in the Size Wing.
Gloria didn't want to shrink herself. She was already tiny. What would be more fun would be becoming huge. A giant fly would be a monster, and she could give some of the resort guests a fun little scare. So she flew off to the smallest tunnel entrance she could find, barely fitting through. This would mean she would barely fit through whatever door she exited, of whatever size. In the darkness of the tunnel room it was hard to see what size exactly she would be coming out through each door, so she found a big door and flew back out into the world.
It was perfect. She was huge, several times taller than a normal-sized person. She flew outside to the pool and lounge area, and sure enough, everyone started fleeing in panic. Gloria figured she might as well do what a fly does, and she flew towards a random woman and shoved her giant fly mouthparts into the woman's stomach, gorging herself on the human woman's blood. It was glorious to know that she was wreaking havoc and instilling terror all around her, but in practice there wasn't enough blood in a human body for a giant fly like Gloria. So she flew around a while, easily outpacing the fleeing people and attacking whoever she saw fit. It was great. At one point she even gorged herself on a ten-foot-tall teenager who hadn't taken quite as much advantage of the Transformation Resort as Gloria had.
After a few minutes, she saw a group of people come running out of a door in the standard Transformation Resort uniform. For whatever reason, they seemed to have a problem with a huge fly flying around the resort and feeding on humans.