"Alex!"

The desperate yell of her sister made her look up. She saw Kara, in her Supergirl uniform, standing at the now sealed door of the med bay, her hands pressed up against the glass and her face showing pure panic.

It was hard to hear anything over the sound of the still blaring alarm. Just when Alex crawled up to meet her sister at the door, the fluorescent lights went out, bathing the room in the red emergency light.

Alex managed to get up from the floor, as Kara moved to the touchpad to open the door. "I can't… open it!"

"I know." Alex nodded, her expression nothing but seriousness. "I activated emergency protocols. Did you get him?!"

"Get who?! I just flew in from my rounds when everything went in lockdown!"

Alex's stomach dropped. She prayed that the alien would still be inside the DEO. Super speed could be a factor; if he had managed to escape, he'd be long gone.

"The alien, Kara. You need to find the alien."

Kara frowned, and opened her mouth to no doubt ask for details, when her eyes widened at the sight of Maggie behind Alex. The detective was sitting up, her back leaning on the now vacant bed. She was clutching her shoulder, but she was awake, and looked more pissed than anything else.

"Alex, what happened?!"

Before Alex could explain anything, Kara looked to the side. She watched as J'onn, Winn and Amelia Hamilton, the leading medical expert of the DEO, walked over to Kara.

"For god's sake, somebody shut down that alarm!" J'onn growled in his earpiece, before he looked at his second-in-command behind the glass. "Alex. You okay?"

"Emergency protocol." Alex replied, getting down to business instantly. "The alien got away, he must still be somewhere around here. I activated the lockdown as soon as he ran out."

J'onn nodded. "Agent Schott is tracking him; he's hiding somewhere in the basement. There are agents already getting ready to capture it."

"Tell them to wear full body armor, and helmets. It bites."

She could see Kara's eyes looking up and down, trying to see where it would have bitten Alex. The agent sighed, and looked back at Maggie's form on the ground, still clutching her shoulder.

Finally, the alarm shut down, and the building went eerily silent.

"What's that puncture wound?" Amelia asked, pointing at Alex's neck. Her hand went down to the wound once again. "One of the alien's fingernails. I put it down over there. And I still have the alien's samples, I was on my way to test them when he woke up."

"Okay, so open the door and give them to-…" Kara started, but both J'onn and Alex interrupted her at the same time with a resounding "No".

"It's too dangerous. We don't know what it can do, the bite could be contagious."

"We're completely in the dark." J'onn grunted, realizing how grave the situation was. "Agent Schott, keep tracking the alien. Supergirl, maybe go see if the Fortress of Solitude has any information on the alien?"

Kara shot one last worried glance at her sister, before running off. Alex watched her go, before her attention was pulled back by J'onn. "It was a good call to activate the quarantine."

He turned to Amelia. "I'm going to go help detain the alien. Can you…"

The doctor nodded with a smile, before looking back at Alex when the two of them were alone. "Hey, Alex."

Alex chuckled weakly, running a hand through her hair. "I've been at it for hours trying to analyze the anatomy and DNA, Amelia, I don't know anything."

"Okay, easy." Amelia looked serious, as she raised the clipboard she'd been holding. "If I can't come in, you're going to have to do it yourself, okay? Can you do that?"

Alex nodded quickly, balling her hands into fists. She needed to be professional. She'd been quarantined before – if she kept a level head, everything would be alright.

"You said you still have samples?"

"Yeah, they're on a tray here. Saliva, tissue, hair…" Alex trailed off.

"Okay. And you have equipment set up for analyzing?"

"Not as much as in the lab, but we have some microscopes and centrifuges here." Alex glanced around the room. "I'll start working right away."

"No, hang on, hang on." Amelia stopped her. "The two of you. Medical first."

She looked behind Alex, to where Maggie had been following the entire conversation from her spot on the floor. "Detective Sawyer, how are you feeling?"

"I've had worse." Maggie grunted, still nursing the bleeding spot on her shoulder. "Don't worry."

"We'll treat it like a venomous bite for now, until we have a better view of the situation."

Alex nodded. Amelia sighed. "I have no more expertise here than you, but I'll try and keep you updated. Agent Schott is monitoring the camera's here, so if anything goes wrong, I'll be here in less than 30 seconds. If you need me, call me on the touchpad, okay?"

"Where are you going?" Alex asked.

"We need to work double time on this. I need to go brief the bio team so they can continue your research. But I'll be back as soon as possible, Alex."

After another quick 'good luck', Amelia rushed out of the corridor.

"Shit." Alex heard Maggie's defeated sigh behind her. She turned around, and walked towards her girlfriend, who was now grimacing. "Hey, are you okay?"

"Peachy." Maggie hissed. Alex reached forward to examine the wound up close, but frowned when Maggie pulled away quickly. "Don't… don't touch it!"

"Why? Does it hurt?" Alex asked, getting up from her crouched position to start gathering medical supplies from the cabinets. She tried ignore how much her hands were shaking, and willed herself to stay calm. She was a trained field operative, for god's sake. This was a cakewalk. She just had to stay calm.

"Only when you touch it."

Alex tried to remember her training. Venomous bites.

No exertion, no incisions, no covering the wound.

"Do you feel dizzy? Nauseous? Does your head hurt?"

"None of those." Maggie shook her head. "It's just… pulsing."

Alex nodded slowly. The fact that she had no real symptoms of poisoning was at least slightly reassuring. "What about blurred vision? Can you see alright?"

"I feel fine, Alex."

"Okay, I'm just going to clean the wound, alright? But it's going to hurt."

Maggie chuckled weakly. "I'm not a kid, Danvers, it's fine. Do it."

As Alex moved closer, she saw the wince on Maggie's face return. She had to be quick; if the alien really had been venomous, then it could have already spread through her entire body with unforeseeable consequences.

"What about you? Are you okay?" Maggie gritted through her teeth, looking up as Alex moved closer. Upon her pressing a gauze pad to the wound, Maggie finally cried out in pain, looking away.

Alex was breathing through her nose, trying to hold her composure. Don't think about it… Focus on what you're doing… Don't…

"Stop… stop…" Maggie pleaded weakly. Alex pulled back the gauze immediately, and looked up. "I'm sorry…"

Maggie shook her head, dismissing the apology. But the sweat appearing on her forehead and her ragged breaths did nothing to ease Alex's mind.

"What kind of pain is it?"

"It burns… But it kind of comes and goes."

"Just the shoulder?"

Maggie looked uncertain, as she thought about it. "My head too."

Alex took a deep breath. "Okay, so, definitely something…" She looked back at her girlfriend. "Babe, everyone here is working on it. We're going to get an antidote soon, alright? Just… stay with me."

"The floor is getting hard." Maggie said.

"I don't want to move you around too much. That'll make it spread faster." Alex said, biting her lip. She really didn't want to make it worse, but obviously Maggie couldn't stay down on the ground for the foreseeable future.

"I'll be quick." Maggie grunted, getting herself up from the floor. Alex moved in to help her, by putting a hand on her lower back. But the second Maggie tried to lift herself up from the floor, she dropped back with another yell of pain.

Alex's eyes widened, as she moved forward to steady her, but that only made it worse, as she continued her painful screaming, tears now streaming down her face.

"Maggie!" Alex was at a loss. She was crouching down in an unnatural angle, and decided quickly to pull Maggie up in her arms – ignoring the screaming – and place her down onto one of the vacant beds.

She turned around to rummage through the drawers to get an IV set up. Maybe some morphine would at least ease some of Maggie's pain. Because the screams cut Alex to the bone, and she never wanted to hear the desperate crying again.

Maggie had stopped screaming, and was now breathing heavily. "Fuck… fuck, that hurt…"

"Is it better?" Alex asked, as she was hanging the saline solution on the stand.

"Yeah… I think it's over."

A loud knocking on the door of the med bay made the both of them look up. Amelia and Winn were standing wide-eyed on the other side. Alex ran over to the door.

"Is she okay?" Winn asked immediately.

"Better now." Maggie replied from her spot on the bed, already moving to sit upright. Amelia frowned. "Maggie, stop moving."

Alex watched the detective ignore the plea and swing her legs over the side of the bed to sit up. She turned back to her coworkers. "No dizziness or blurred vision, no fever. No other symptoms. Just random spikes of pain. I'm not sure it's actually venom."

"We can't rule it out, Alex." Amelia shook her head. "What are you thinking?"

"I have no idea."

A beep from Winn's tablet made him frown, as he tapped the touchscreen a few times. "They lost the alien. He still has to be inside, but they can't find him anywhere…" He looked up. "Maybe he's a shapeshifter? Or maybe-"

"He's in the armory."

Alex felt three pairs of confused eyes land on her. Only seconds later did she realize that the voice had been her own.

"Uh…" Winn frowned, and tapped his tablet a few times, swiping through the camera feeds all around the building. Finally, he found the feed of the armory, and his eyes widened. "Holy…" He pressed his earpiece. "J'onn, he's in the armory on the second floor!"

His wide eyes snapped up to meet Alex. "How did you know that?!"

"I…" Alex seemed taken aback by her own statement. "I don't… know? I just… knew."

"Babe…" Maggie's shaky voice. Alex turned around to see her lover staring at her. "Come here. Slowly."

"What?" Alex asked, confused at the command. But Maggie didn't seem in the mood for jokes. "Come over here, one step at a time. Slowly."

Alex glanced back, but Amelia and Winn seemed as confused as she was. Carefully, she took a step in Maggie's direction. And another one, and then another one. Keeping her eyes trained on Maggie at all times. But the detective didn't seem to respond until she was a few feet away.

Alex noticed Maggie's breathing getting faster, and concern took over her body once again as she took a big step into her direction. Was Maggie trying not to make them worry? Was she trying to downplay her symptoms?

As Alex approached her and reached a hand out to her, Maggie suddenly doubled over on the bed, both hands clutching her head. Alex yelled out her name and put a hand on her good shoulder.

She didn't expect Maggie to shove her away so forcefully that Alex was knocked off balance, and tumbled onto the ground, taking a tray of surgical equipment with her on the way down.

After the loud clattering of the tray had died down, the entire room went silent.

Amelia and Winn were both frozen at the door. Maggie was breathing heavily, her eyes wide at the realization of what she'd done.

"Maggie…?" Alex whispered, the confusion clear in her voice.

"It's better…" Maggie said, more to herself than to Alex. Finally, her eyes landed on her girlfriend's form on the floor.

"It's you, Alex… You're hurting me."