A very short, but fun one shot where we see where Gibbs got his famous head slap from. I hope you enjoy it. Crossover with NCIS: Los Angeles. Gregg.

Disclaimer: I don't own, or profit from, these characters or franchise. No copyright infringement is intended.

"Since I need to attend this conference in London, I am leaving in charge a specific person for the next week," NCIS Director Leon Vance said, a wicked grin on his face around the ever present tooth pick.

"Just as long as they don't mess with me or my team, Leon," Gibbs postured. He certainly didn't want to take over for a week, but he also usually despised the efforts of whoever else was left in charge to "lead" Gibbs and his team.

"Oh, I have someone special, Jethro," Leon replied. "The one person who you absolutely can't say no to. Who you've never been able to say no to."

Gibbs' head shot up and he looked incredulously at Vance, not caring that his team was now looking at him strangely. He stood up and came around his desk to face Vance eye to eye. "No," Gibbs protested. "You can't do that to me, Leon."

"I already did," Leon gloated in that wry, understated manner of his.

"I won't work with her," Gibbs stated flatly.

"Leroy Jethro Gibbs!" came a very strident, yet calm voice from behind him.

Everyone watched as Gibbs turned and looked down on a very short, thin, diminutive older lady with round, tortoise shell glasses on who was looking up at him, a firm expression on her face. He plastered a fake, insincere smile on his face.

"Hello, Hetty," he said in as unsullen a voice as he could muster.

"Down," she directed him.

Gibbs, feeling humiliated right then, but not able to do anything else, sighed and bent at the waste so he was eye to eye with the woman.

WHACK!

The rest of the team, DiNozzo, Ziva, and McGee watched as the older, tiny woman gave Gibbs a head slap!

"It's always a pleasure to work with you, Hetty," Gibbs said instantly as he rose up straight, rubbing the back of his head. Damn, she could pack a solid head slap!

"That's what I thought you said," Hetty said with a slight, enigmatic smile.

"So that's where the head slap comes from!" DiNozzo said with obvious delight that the Boss was not immune to a good head slap. He leaned over to Ziva and stage whispered, "The Boss is so whipped!"

"Anthony!" Hetty said firmly with a finger pointing to right in front of her.

DiNozzo stepped right in front of her where she was pointing.

Hetty looked up at Gibbs. "Jethro?" she said, her eyes glancing DiNozzo's way.

Gibbs smiled as he delivered a solid head slap of his own.

"Thanks, Boss," DiNozzo said as he walked back to his place, rubbing his head.

"I'll leave you in Gibbs' capable hands, Hetty," Leon said, a smile still on his face.

"We'll be just fine, Leon," Hetty said as she slipped a hand in the crook of Gibbs' left arm. "Let's go have some tea, Jethro, and discuss your current cases. I have an excellent blend from Nepal that you absolutely must try..." she said as she began walking, with Gibbs, right out of the bullpen.

"Sounds great, Hetty," Gibbs could be heard saying by the rest of them.

"Tea?" DiNozzo asked, thunderstruck.

"Gibbs?" Ziva and McGee said in unison.

Leon chuckled as he left the bullpen. "No one says no to Hetty," he told them as he left to go get ready for his trip. He made a note to make sure that all security discs were saved so he could watch how she runs roughshod over Gibbs for a week. He'd stock up on the popcorn for that show.

A/N: I couldn't resist this one and using Hetti as a prime character for it. I hope you all enjoyed this short look at the origin of Gibbs' Head Slap. Gregg.