Danny took Jenny for a fly around Amity Park. Jenny followed him, smiling. She got the hang of flying with some instruction from her brother.

"When can I go invisible and fly through walls?" She asked.

"You are still learning. I didn't even learn everything in a day. It took lots of training. But you have always been a smart kid. It's only been a half hour and you're flying like a pro with your tail…although at first you did crash into a few trees while learning. I'll teach you to turn invisible. It's not too hard. Just focus and don't show fear. You can totally do it." Danny explained.

"You are right. I'll get the hang of my powers, just not all of them overnight." Jenny said as she flew into a tree. She didn't phase and ended up crashing again. "I don't get it. I thought if I knew flying and turning invisible I might be able to take on another ghost. And no I'm not going to fight my own brother." She added.

"Afraid you might hurt me?" Danny chuckled.

"Not exactly. I can't even shoot a plasma blast that well." Jenny said as her anger got the better of her, her fists glowed green and she launched a perfect plasma blast.

Surprised, Danny barely managed to avoid the blast. "That's good but try not to let your emotions get the better of you." He said.

Suddenly their ghost sense let them know they weren't alone. "Skulker. Why am I not surprised." Danny said. He gave Jenny a look as if to tell her to fly away.

Jenny rolled her eyes but obeyed as she turned just in time to see the box ghost. "You're a sorry excuse for a ghost." She said as the box ghost threw boxes from the surrounding area at her. She was able to phase through them and punch him hard. She then caught him with the Fenton Thermos. Jenny made sure it was closed tight before going to help Danny with Skulker.

"You just can't stay in a Thermos long can you." Danny smirked as he sent a volley of plasma blasts at Skulker.

Skulker tried to attack Danny and almost hit Jenny. If she hadn't phased he would have. "You are still learning your powers I see. You beat me once girl but now I will end you both.

"Get behind me and cover your ears." Danny ordered his sister, as soon as she had he used his Ghostly wail.

When Skulker was blasted to the ground and too weak to continue, Jenny shot him with a single Plasma Blast before capturing him in a Fenton Thermos.

"If we hurry we can probably catch a movie with Sam and Tucker." Danny said. "I'd train you some more but I bet if you're anything like me, you'll be good at fighting the next ghost we run into."

Jenny smiled at her older brother as they made their way back home with the Fenton Thermos. As they flew, Jenny asked her brother, "Hey Danny, is it just me or is it really hot, even for a summer day?"

Danny raised an eyebrow and replied, "Are you really that hot, or is that sweat from fighting Skulker?"

Jenny wiped sweat from her brow as she replied, "I think it's a bit of both. I don't feel so good…" before falling into an alleyway as she turned human and passed out.

Danny's eyes widened and he flew after her. He changed back to a human and felt his little sister's forehead. It was obvious she had an intense fever. He called Tucker on his PDA and told him, trying to avoid panicking, "Tucker, get Sam and meet me at my place, Jenny isn't doing so well, she just passed out and she's got a heavy fever." before picking his little sister up and running home as fast as he could.

When Sam and Tucker arrived, Sam told them, "I already called 911, they should be here soon. Is Jenny ok?"

Danny shook his head, "No, this fever is really high, she hasn't woken up yet either." as they heard the sound of ambulance sirens, Danny told Sam and Tucker, "Go get my parents, they may not know our secret, but they'll be worried too."

Tucker ran inside and told Jack and Maddie that Jenny had a high fever and that the ambulance just pulled up.

As they ran outside, Maddie asked the EMT, "Is she going to be alright? Please tell me she's going to be alright!" tears leaking through her jumpsuit

The EMT told her, "We're doing our best, but she's running a fever of 120 degrees. That's not normal, but I promise, we'll do everything we can to help her recover."