Elle made her way to the Chem Lab, a spring in her step. Spock had moved their class there for today. She paused on the threshold and looked at the rows of scientific equipment and assorted tools. "Uh, Spock?" she called, edging closer to the table.
He came out of the adjacent store room. He handed her a small lab coat, a pair of nitrile gloves, and a pair of safety goggles. "Safety first," he said gravely.
Elle gave him an innocent look. "Where's your goggles?" she asked.
He produced another pair of goggles, gloves, and lab coat in his size. "Hydrogen peroxide can cause skin or eye irritation," he informed her.
"Cool. So, what are we doing?"
"We will be using hydrogen peroxide and standard issue soap from the Maintenance department and recording the results of mixing the two ingredients together."
"Will it explode?" Elle asked, eyeing the tall beaker and the spillover pan.
"It might," Spock said. "If we do it correctly." That was definitely a not-smile in his voice. "There is always an element of risk," he continued dryly. "It will be harmless."
She grinned at him. "Awesome."
They proceeded methodically through the weighing and measuring of the ingredients, recording it all on a PADD. Then Elle added the catalyst and hit the blend button.
The chemical reaction roared forth out of the glass bottle and overflowed the spill pan. Before Elle could blink, the foam grew and covered the table, then the floor. And then it kept going, and going, and going...
Before Elle could move, the foam was bubbling around their ankles, spreading over the floor of the lab. She looked at Spock, fighting back laughter. "Uh, Spock? Was it supposed to do that?" she asked.
His eyebrows were in his hairline. "No," he said. "This is... unexpected."
Elle lost it, giggling hysterically into her hands as the foam reached her knees. "This is crazy!" she said. "When's it going to stop?"
"As I do not know what made it grow exponentially, I cannot estimate accurately," he said, looking vaguely alarmed. "I neglected to prepare a counteragent. However it should stop once the catalyst is consumed."
It reached Elle's waist and triggered the door sensor, spilling into the hallway. "Uh-oh," Elle said, giggling helplessly.
The biohazard and the containment breach alerts were triggered a moment later.
Spock sighed.
It was definitely past Elle's waist. She started wading through it, trying to get to where she thought the chair was, in case it got higher. She couldn't actually see it. Everything was lost in a sea of green foam. She gave up on the chair and turned to look at Spock.
He looked back at her impassively. "We must wait," was all he said.
Elle carefully scooped up some foam, and placed it on his head. "Now you have a hat."
He blinked at her, his other eyebrow rising, and then deliberately mirrored her actions, plopping some foam on her head.
She giggled.
At that moment a medical team, a security officer, and another science team burst down the hallway. They paused at the fringes of the foam, gaping.
Of course it was McCoy in the lead. He saw them, took in the lab coats, the foam, and started to grin. "Why Mr. Spock," he said, grinning from ear to ear, "I always knew you were mad scientist." He hit the wall comm. "Captain Kirk to Chem Lab 1, immediately!"
"On my way!" came Kirk's worried tone.
The two scientists, to their credit, were trying their hardest not to burst into laughter at seeing their commanding officer standing waist-deep in foam with a perfect foam hat. "I'll call Maintenance," the lieutenant said, and fled.
"I'll cancel the alarms," the other ensign said, voice choked with laughter, and escaped, snickering his head off.
The security officer cleared his throat. "I'll just, uh, leave you to it, then, Mr. Spock?" And he was out of there.
Elle leaned against the wall, giggling helplessly. McCoy joined her, literally slapping his knee as he laughed.
The captain came skidding around the corner and actually made it two steps into the foam before skidding to a halt, sending foam flying. He froze. And blinked. And turned to stare at his science officer. A smile twitched at the corner of his mouth. "Spock...?"
"A miscalculation in measurements, I believe," Spock said, deadpan.
Kirk covered his mouth with his hand and gave a suspicious cough. "I see," he said, his shoulders shaking.
Elle cheerfully scooped up some foam and lobbed it at McCoy. It squished against his uniform. "Foam fight!" she declared, and hid behind Kirk.
McCoy spluttered in disgust. "Oh, don't start something you can't finish, missy," he threatened, and splashed her with the foam.
Of course, Kirk took the full brunt of it and he retaliated quickly.
"I call Spock!" Elle yelled.
As one, Kirk and McCoy turned to look at Spock, who gave them a definitely-not-panicking expression. They grinned in sync, and advanced on the Vulcan.
Elle started lobbing handfuls of foam at Kirk and distracted him enough for Spock to make a preemptive strike on the doctor.
By the time the maintenance crew got there, they found four foam monsters splashing about in the foam that was slowly dispersing down the hallway. Three out of the four foam covered people were laughing so hard they were almost crying. The fourth was impressively deadpan, except you couldn't see his eyebrows underneath the foam.
"Um... captain?" Lt. Senegal asked uncertainly.
Kirk flapped a hand weakly, half leaning on McCoy's shoulder. "Just leave everything here, lt, we'll clean up. Dismissed."
"...Yes sir?" They dropped the stuff and beat it.
Elle grabbed a bucket of water and poured it over her head. The foam dissolved instantly, and she blinked wet hair out of her eyes.
Kirk picked up a wet-vac and started to vacuum up the foam into the water tank. Spock picked up the other one. McCoy took great delight in dumping the water over Kirk's head, and then his own. He looked at Spock and gave an evil grin.
"There is a perfectly functional sonic shower in the decontamination room adjacent," Spock said severely.
"This is more efficient," McCoy said.
"Vulcans do not get wet," Spock replied.
"Bones, leave 'im alone," Kirk said, still chuckling periodically.
Elle picked up the dry vac and followed along behind him, blowdrying the floor.
Once they were done, Kirk and McCoy left them to pick up their things. "Let's try not to set off any more alarms," Kirk told Spock.
Spock inclined his head. "I cannot make any guarantees, captain, but we will make the attempt."
"I knew he was mad scientist at heart," McCoy muttered, as Kirk dragged him away.
Elle giggled and turned to face Spock. "Greatest day ever," she told him.
His eyes softened, but all he said was, "We shall have to investigate why it reacted that way. Next class we will examine the chemical composition of both ingredients."
She grinned. "Yes, sir."
When she got to her quarters, her computer beeped with a waiting message. Someone had sent her a picture, pulled from the security footage. It was her and Spock, staring at each other with matching expression of shock, foam blobs on their heads.
Elle saved it to her personal file, and after a second's contemplation, sent a copy to Lady Amanda.