Pan was beyond angry, beyond furious even. He had actually trusted her, and she took advantage of that. Gianna, known to the Lost Boys as Gia, was the first.
First girl to come to NeverLand on her own, not taken by Pan's shadow. First girl to pass Pan's tests and games, firstgirl to get Pan to trust her, thus getting her freedom to roam NeverLand, and most importantly, she was the first person ever to leave NeverLand without Pan's permission.
When she first came to NeverLand, Pan was going to kill her right there on the spot. However Gianna was a very smart girl, so she proposed a challenge; if she could last a night all alone, she gets to live. Pan accepted. She had managed to avoid Pan's Lost Boys for two days. Pan couldn't believe she managed to last not one, but two days on her own. Impressed was an understatement. He allowed her to come to his camp, where surviving would be easier.
So that's where she lived for a while, gaining the Lost Boys' trust and respect. But after a while never growing up began to bore her. She was 16 when she first came, and she should have been almost 19 when she made her escape. She never asked about leaving before. She didn't want Pan to be suspicious of her trying to leave.
She snuck into Pan's tent while he was out. Her going into Pan's tent was no big deal; she slept in there with him. She had her own bed, dresser, and wardrobe. However, she knew she wasn't supposed to go into Pan's desk, that's where he kept his magical and enchanted items. Since Pan wasn't at camp at that moment, Gianna decided it would be the perfect opportunity to see what she could find, hoping something would help her leave.
She found portal beans in a small drawer of the desk. She took 2 of them and left before Pan caught her. She left that night. Pan was so angry because he and Gia were really close. He wouldn't admit it to the Lost Boys, but he liked her quite a bit. He used enchanted maps to track her down. He knew he would find her. 12 days after Gia made her escape, Pan's shadow brought her back.
She was caged and kept in Pan's tent like a pet. She was only allowed to be out when Pan was around and awake. Some Lost Boys felt bad for her but knew not to go against the bloody demon that is Peter Pan. Gia didn't regret leaving. It was fun until she got caught. She tried many times to apologize to Pan, but he wouldn't hear it. She was kept caged for over two centuries.