Leo suddenly awoke from the wonderful Disneyland dream he was having with extreme nausea. He tried to take deep breaths to stop the overwhelming feeling that he was going to puke. He didn't like throwing up, even though he did it often, mostly because he had a weak stomach and anxiety. He tried so hard to calm his upset stomach, but five minutes later, he made a mad dash down the hall to the bathroom, hoping he wouldn't puke all over himself and the rug.

He made it just in time. Disgusted by the pile of sick he created, he threw up even more. Then, exhaustion came over him, and he fell asleep on the floor while flushing the toilet. He woke up again three more times that night, each time feeling incredibly nauseous before emptying his stomach into the toilet. Leo was surprised at how much was in him. He did have a huge dinner the night before, so he figured that was the reason.

At 5:30 am, Jemma got out of bed (she was quite the early bird,) and went over to bathroom. Immediately she was hit with the sickening smell of vomit. She looked around and saw Leo passed out on the floor.

"Oh, Leo, wake up," she said as she gently shook him. He opened his eyes and looked weakly at Jemma. The smell of vomit made him even more nauseous, and he started retching with his head in the toilet, which progressed to puking yet again. Jemma had a strong tolerance for gross stuff (biochem was full of it,) so she just patiently waited until Leo was done, completely fine. She helped clean him up and made him swish mouthwash, which made him feel more nauseous.

"Dear, dear, Leo, what did you eat last night? Or where did you get this stomach bug?" Jemma asked him.

"I dunno…" he groaned.

"How are you feeling? Can you tell me your symptoms?"

"Y'know, extreme nausea, I feel super weak and tired, and my head feels all foggy and dizzy. I'm achy all over too," he explained.

"Let's get you into some clean pyjamas. I'm going to take you to the lab and take care of you. I think you're quite dehydrated," she said to him, helping him walk to his room to get some new clothes.

Five minutes later, Leo was laying on a medical bed in the lab propped up because it made him feel a bit better. "Jem, why do I have to be sick? I have a bunch of things to do!" He said sadly as Jemma examined him, taking his pulse and other vitals.

"It's alright, Fitzy. I also have things to do. But it looks like we're both taking a day," she reassured him.

"I might be taking a day, but you're not. I'm sorry, Jemma," Leo replied apologetically.

"It's alright, Leo. Really. I'd rather take care of you."

"Really?"

"Uhhh… okay, its not on my top ten list of things I'd rather do, but it's still up there," Jemma said honestly.

Leo felt yet another wave of intense nausea come over him. He tried to take deep breaths to get out of it, but his mouth was watering. "Jemma! I need a bin! Now!" He shouted. Jemma tossed him a plastic wastebasket that he proceeded to throw up into. After he was done, he groaned and said, "Oh, Jemma, I'm so gross. But please take the bucket away, I swear my own barf makes the feeling worse." Jemma took the trash bin and took it over to the lab. "I'll analyze this later. But right now you need fluids. Think you can stomach some water?" She said.

"Wait, you're going to analyze my barf? Ewww… I'm glad I don't do biochem…" Leo said with a weak smile. Jemma came over with a water bottle with a straw in it and told him to take small sips. He had another bucket on his lap just in case. After two sips, it just came back up. After he attempted to take a drink three more times, Jemma decided to start an IV.

"No no no no no, you know I don't like needles!" Leo whimpered as Jemma rolled the supplies over on a trolley, along with the pole. He hid under the blankets as he also spotted some bloodwork equipment laying there as well.

"I'm sorry, sweetie. If you can't hold water, you need to get it another way. And I'm worried about you. I've never seen you this sick. I have to take some blood samples so I can test for certain… things," Jemma said to him in a soft voice, trying to calm his squirmy anxiety. She gently shushed him and softly laid her hand on his shoulder.

"You'll be alright," she reassured him, "just… focus on my voice. It'll be okay. Hold still." She took a tourniquet and tied it around Leo's upper arm, felt the veins in his inner elbow, and soaked a cotton ball in antiseptic. Leo was now cowering and looking away from what Jemma was doing. He wouldn't stop shaking and he was holding his breath. When Jemma touched the cotton to his arm, he jumped.

"Sweetie, you've got to relax, okay? Just breathe with me, don't look at what I'm doing, you'll probably puke or even faint. I'll guide your breathing, okay? Ok, breathe in. One, two, three, four…" she said as she finished cleaning his arm and inserted the needle. She made sure to be extra gentle while switching the vials. Even through she was coaching Leo's breathing and constantly reassuring him, he looked very pale. She taped a piece of cotton to his arm after she finished, then turned to Leo and patted his sweaty, pale forehead with a cloth. As he tried to take some breaths to calm down, he grabbed the bucket and threw up once again. After Leo finished, Jemma put an IV into his arm to reverse his dehydration.

"Ok, I'm going to go run some tests on the samples. I need you to rest here. Give me your arm," She said as she grabbed a soft elastic bracelet off of the counter.

"What's this?" Leo asked as she positioned the red wristband's plastic piece on a certain point on his wrist.

"Anti-nausea wristband. It presses a nerve point that can relieve nausea for some. If it works, great. If it doesn't, well, it was worth a try. If you need anything, just holler. Here's a new bucket," she said, handing him a clean bucket and walking over to her biochemistry equipment. Doing work with samples was always absorbing for Jemma; everything always seemed to melt away and it was just her and the task at hand. An hour passed, even though it felt like half that. Some weird results kept popping up in the tests.

Jemma was about to look into this when she heard Leo calling out from the other room, which snapped her out of her hyper-focused state. She ran over and saw him hunched over, hugging his chest and abdomen while groaning in pain. "Oh, Gosh!" She yelled as she ran back and got her cart full of medical supplies, and swiftly wheeled it over.

"Leo! What's wrong? Where does it hurt?" She asked him as she plugged in the EKG in case she had to monitor his vitals.

"My chest… it's all tight… it hurts… it hurts really bad… my stomach… too… I. Can't. Breathe…" he whimpered between gasps. Jemma got out her stethoscope and tried to comfort Leo by putting a hand on his shoulder. She listened to his chest; his breathing was rapid and his heart was pounding, and sounded rather odd. She swiftly hooked him up to an EKG monitor and saw something that alarmed her greatly. It was a dangerous heart rhythm that needed to be corrected or Leo could die. She was surprised that he hadn't lost consciousness yet.

"Leo, I need you to hold absolutely still," she said as she got a defibrillator from the corner of the room.

"What? I'm not flatlining…" he squeaked.

"That's a bloody television myth, Leo! You don't shock a flatline, you shock a ventricular tachycardia!"

"A what?" He asked in a weaker voice.

"Hold still!" She demanded as the defibrillator charged. She she placed the paddles on his chest, then delivered the shock. His body jerked upward as he was instantly knocked unconscious by the jolt. Jemma quickly looked at the monitor and sighed in relief as it showed his heart rhythm was back to normal. It's definitely not a stomach bug, she thought anxiously, I've got to finish that bloodwork. She grabbed a device that Leo named the "baby monitor," which was basically a camera that connected to the vital monitors that displayed the video and vital sign readings on a separate screen. Jemma set up the screen right next to her station and continued analyzing the samples.

Some strange toxins were present in his blood; Jemma had to flip through three books and finally looked through a SHIELD research database to figure out where they could have come from. And then she found it: A deadly compound known as ARA-25. Jemma hypothesized that he must have been poisoned by touching something contaminated on the team's least mission; if the chemical was in the air, everyone would have been affected.

Using this information, Jemma began working on an antidote that would neutralize the poison in Leo's bloodstream so it could stop harming him. She sighed as she looked at the baby monitor and saw her friend lying motionless on the hospital bed. Once again, she fell into a hyper-focused state, the knowledge that she will cure her friend driving her. Coulson came in to check how she and Fitz were doing and had to shake Jemma to get her attention.

"Hey, you alright?" He asked her in his soft voice.

She looked up at him and said, "I'm fine. Just very focused, that's all. I want to create this antidote before Leo's condition gets any worse."

"Keep up the good work, Simmons. I believe in you," Coulson said with a smile and a pat on the back.

The next two hours were full of trial and error as she mixed different substances in different ways and tested their effects on a sample of ARA-25 that Jemma created herself. The longer it took, the less focused Jemma got, she was worried that Leo would deteriorate more if she didn't get it done. Every five minutes she looked up at the baby monitor and made sure all the vital numbers were in a good range.

When Jemma saw the result she was looking for using the 28th version of her antidote, she jumped for joy. It was like finding the cure to a deadly disease. She quickly ran over to Leo, who had regained his consciousness and was having his temperature taken by Grant (he was asked by Coulson to make himself useful.)

"Leo! I did it! I've created an antidote!" Jemma said as she came over with a syringe full of the serum.

"I was poisoned?" he asked, alarmed.

"Yes, you were exposed to something hazardous yesterday. Don't worry, no one else on the team tested positive for contamination. I've developed a fully functional antidote, though!" She said with a smile, "I'm just going to push it into the IV now, it will probably feel cold." Leo winced as she pressed the plunger, sending the serum into his bloodstream.

When she finished, Leo quickly said, "Ok, cool. Can I do my work now?"

"Nope. You've got to stay in bed. There might be side effects that we don't know of," she replied.

"I… I think you're right…" Leo said as he laid back on the pillow, his eyelids heavy. He suddenly felt unbelievably sleepy.

"If you're feeling fatigued, just let yourself sleep. I'll be right here, monitoring your condition," she reassured him. Leo smiled and closed his eyes.

"Well, crisis averted! Leo's not succumbing to poison today!" She said to Grant, putting the syringe down on a nearby tray. She petted Leo's fluffy hair and felt content knowing he was going to be ok.