Nick was ticklish, as they discovered when TJ finally managed to get the stethoscope under his too-big, white T-shirt.

This was very, very hard to not exploit.

"I'm gonna getcha," Greer growled, angling his body so Eli's hovering Kino could record. He wiggled his fingers, getting closer and closer to the already-pinned little boy. "I'm gonna getcha."

His fingertips brushed against Nick's stomach and the boy let out a howl of laughter. His left leg soared up and his foot connected hard with Greer's jaw, sending the man sprawling.

Eli tried and failed to stifle his own laughter.

"Oh, man," he wheezed. "Oh, that was awesome. You just got pwned, dude. And he's, like, four."

"I'm six!" Nick said, jumping to his feet and kicking Greer again in the side. The marine's hand shot out, grabbing Nick by the ankle. In the next moment, Greer was standing and Nick was dangling upside down, his face red from a mixture of giggles and blood rushing to his head.

"OK," said Eli, unable to choose between watching the Kino remote and what was going on before him. "Um, maybe we're getting a little too rough."

Nick head-butted Greer in the balls.

Greer sat on him.

Eli frowned. "Or not," he said.

"Greer," called Young, who had hitherto just been observing. "It's a tickle fight, not Battle Royale. Let him go."

Greer rolled off Nick, muttering something that sounded like an affectionate, "little fucker."

"Big fucker," Nick retorted.

"NICK!"

"Sorry!"

Frowning, Young turned back to his paperwork. He had read maybe a paragraph when he felt a presence at his elbow.

"What are ye doing?" Nick asked. Young raised his eyebrows and tilted his head.

"Work."

"Nuh-uh."

"Yes," said Young through gritted teeth. "Yes-huh."

"That's not work," Nick argued – admittedly, a lot more good-naturedly than his older self had. "You're just reading."

"Well," said Young, "sometimes that's what very important people do."

"My dad doesn't read for work."

"Is your dad a very important person?"

Nick seemed to seriously consider the question. Young gaped at him.

"No," the boy said finally. "But he is to me."

And that totally didn't touch Young's heart. Not at all.

For real.

"But I guess I won't be seeing him anymore," Nick went on, seeming complacent enough with that idea. "Eli says we can't get back to Earth."

Young shot Eli a glare.

"So I should probably pick out new parents," said Nick brightly. He looked around the room. "Not Eli."

"Oh, thanks!" Eli called. Nick turned his head to look at Greer.

"Not Greer."

Greer flipped him off.

It was a long moment before Young realized that Nick had turned again and was looking at him thoughtfully. His heart stuttered.

"Let's go meet the science team," he said quickly, before Nick could open his mouth. The boy's face lit up like the stars.

"Science team? COOL!"

"This is Lisa Park," Young started, pointing to the petite, smiling woman. She put her hands on her knees and got right in Rush's face.

"I bet you want to learn how to fly the ship," she said. Nick's eyes went wide and his head bobbed rapidly.

"You can teach me?"

"Sure!"

Young gave Park a look he hoped she interpreted as 'but not really or I'll skin you.' He thought she got the message.

"And this is Brody," he said, gesturing at the wryly-grinning man.

"Hi, Brody!" Nick called.

"Hey, little man."

"What's Brody do?" asked Nick. The engineer saved Young from answering.

"I fix things," he said flippantly with a nonchalant shrug clearly meant to convince Nick this was a big deal. "I'm the reason the ship stays up."

Nick looked star-struck. "Awesome," he whispered. Young smiled and turned him to face the third member of the science team.

"And this is Volker."

Mouth tight and eyes shuttered, Nick hid behind Young's leg. Volker's happy face fell.

"What is it about me he hates so much?" he lamented, throwing up his arms. Completely unconcerned, Park and Brody shrugged.

As subtly as he could, Young tried to inch Nick away from Volker.

"And here are the consoles," he said, lifting the boy up so he could see. Nick stared at the screens like a six-year-old Everett had stared at G.I. Joes.

"Wow," he breathed.

At the age of six, Nicholas Rush had found his calling.