AUTHOR'S NOTES: When I first started writing my story 'Not All Family Is Blood' I actually had two story lines I wanted to use with the title. And since my first NCIS/Supernatural fic was a hit, I'm going ahead with this story as well. I know I have too many unfinished stories but my brain bounces around like a pinball machine, so...

Story Summary: Sam and Dean Winchester stop in to surprise an old friend whose father was a fellow hunter. But when the man turns up dead, the daughter-Gunnery Sergeant Fiona Brendan-becomes the prime suspect in the murder. The Winchesters then have to work with NCIS to uncover the truth while avoiding being found by the feds.

SUPERNATURAL: Family Ties

(Crossover w/NCIS)

CHAPTER 1

It was strange to see Jethro Gibbs leaving the NCIS squad room early. And not even early for him which was usually around 9:30 at night.

At 5 in the afternoon, Gibbs grabbed his badge and gun and pulled on his overcoat and headed for the door after instructing Tony DiNozzo to keep an eye on things.

Once their boss was in the elevator and the doors had closed, Tony looked at the other two agents: Timothy McGee and Ziva David. "Boss is leaving early. What's up with that?"

"Maybe he has a doctor's appointment or something," McGee suggested, although he doubted it.

But the team could only speculate as to why their fearless leader had left suddenly and much, much earlier than usual.

After a few minutes, Tony made sure the coast was clear before he went over to Gibbs' desk and started rifling through it.

"Tony, what are you doing?" McGee asked, stunned that Tony would go through their boss's desk. Well, not surprised that Tony would go through someone else's desk but rather that he would do it to Gibbs.

"Tony, stop before Gibbs comes back," Ziva warned, but as she said it, Tony held up what looked like an invitation of sorts.

"But then I wouldn't have found this," Tony replied with a smug grin on his face.

Ziva and McGee leaned over Tony's shoulders as they read the invitation. "Who is Fiona Brendan?" Ziva asked, the name not ringing a bell from any of their cases.

McGee went back over to his own computer and typed the name into the search engine, pulling her stats up onto the large plasma screen.

"Very nice," Tony replied, admiring the woman's picture.

"Fiona Brendan," McGee reported. "Currently a Marine Corps Staff Sergeant."

"Currently?" Ziva repeated, slightly puzzled.

"Due to be promoted tomorrow at 11am," McGee replied.

"But what's her connection to Gibbs?" Tony wondered, looking at the plasma screen.

McGee continued to look through Fiona's records and finally, his eyebrows raised a bit. "How about this for a connection?" With a few deft keystrokes, he brought up a photo taken in Kuwait. Zooming in on the photo, he looked at Tony and Ziva.

"That's Gibbs," Ziva said pointing to a younger-looking Leroy Jethro Gibbs on the left.

"So who are the other two?" Tony asked, curious.

"Guy on the right is James Brendan," McGee replied, looking at the computer file. "And in the middle is John Winchester. The three were best friends years ago."

"Answers the question of who Gibbs is meeting so early in the after noon.," Tony mused. "But why wouldn't he tell us?"

For Sam and Dean Winchester, there were very few times when they could make a trip because they wanted to. It seemed that most of their time was spent traveling from one supernatural hunting job to another.

But when they got a call from the daughter of a fellow demon hunter they quickly turned their car—a black '67 Chevy Impala—around and headed towards Washington, DC.

Life had been hard for the brothers growing up and sometimes they had no idea where the road would take them. Being out on the road with their dad was sometimes an adventure and eventually Sam and Dean had come to expect the unexpected.

But neither brother expected the bond that would form with Fiona Brendan, the daughter of one of their father's best friends in the US Marine Corps. Once he'd started hunting demons, John Winchester had pretty much become a loner, accepting help from other hunters only sporadically. But after finding out that one of his fellow Marines was also a demon hunter, John and James had joined forced on multiple hunts.

Older than Dean by 4 years, Fiona was occasionally the mediator between Sam and Dean as they grew up together and while Sam still had a crush on her, Fiona and Dean's relationship was always that of brother and sister, much to everyone's surprise.

"I can't believe it," Dean muttered as he and Sam reached the outskirts of DC.

"What that Fi's getting promoted to Gunnery Sergeant at 34?" Sam asked, a slight scoff in his voice. It had seemed unlikely when they'd first heard the news from Fiona's father but when Fiona herself had called them, Sam had asked about the promotion. When she hadn't sounded exactly happy about it, both Sam and Dean wondered what had happened.

"No, not that," Dean replied, eyes on the road. "Just… the fact that it's been so long since we've seen her last, you know?" Looking over at Sam, he said, "What was it? 4 years ago?"

"5," Sam replied, not looking at his brother, although he could feel Dean's stare. "She surprised me at Stanford when she was on leave."

"Was that before or after you and Jessica became an item?" Dean asked, giving Sam a grin.

Sam was stony for a while and Dean wondered if he'd hit the wrong nerve. But then Sam smiled. "It was before, Dean. And nothing happened. We just talked. Caught up on things."

"Uh-huh," Dean said with a smirk.

x

When they pulled up to the address Fiona had given then, Sam and Dean parked the Impala out on the street and got out, Dean grabbing two wrapped packages from the backseat, one long and one short.

"Dean, what's this?" Sam asked, indicating the packages.

"It's a party, dude," Dean said, grinning. "So I thought a few presents were in order."

Heading up to the front door with Sam behind him, Dean rang the doorbell and after a few minutes the door opened but instead of Fiona there was an older man standing there. Slightly taken aback, Dean said, "Hi, we're looking for Fiona. I'm Dean—"

"Winchester," the older man finished, a slow look of recognition on his face. Standing aside to let the brothers inside, he waited until the younger men spotted the framed picture on a table near the door.

Sam picked up the photo and nudged his brother before handing it to him.

Dean stared at the picture of his father standing with two other men and recognized one of them at the man now standing in Fiona's hallway.

"Your father was one of my best friends," Gibbs said, taking the picture from Sam and looking at the worn-yet much younger-faces. "This was taken right before John was discharged." Setting the picture down, Gibbs studied Dean and Sam. "So how have you boys been?"

"Oh, it's a long story," Dean said, putting on a smile.

"Let me guess," said a female voice from the stairs. "Diners, motels, and living out of that Chevy Impala." As Fiona came down the steps, she smiled at the two brothers. "Sam and Dean. How long has it been?"

Dean was about to answer when Fiona pushed him gently aside and wrapped her arms around Sam's neck and within seconds, they were in the middle of a deep kiss.

"Ahem," Dean said, clearing his throat loudly. When Sam started putting his arms around Fiona and deepening the kiss, Dean tried again. "Sammy!"

Gibbs chuckled softly and took a step towards the couple and with one swift mood, head-slapped both of them.

Pulling apart, Fiona smiled, happily. "I have been waiting a long time to do that, Sammy."

"Fiver!" Dean said, bracing himself Fiona's wrath. Sure enough, she whirled about on him and before he knew it, he was on his back with Fiona pinning him down.

"What did I tell you about calling me that, Dean?" Fiona said, and although she sounded angry, she had a devilish grin on her face.

When Fiona let Dean up, she shot a false-glare at Sam. "Wipe that smile off your face, Sam."

"Fiver?" Gibbs asked, looking curious at the nickname.

But instead of smiling, Fiona looked saddened as she looked at Dean and Sam before turning to Gibbs. "You remember when Dad and John dropped us all off at your place when Kelly was 7?"

Gibbs remembered that time well as it was right after James Brendan had saved him from a vampire nest. "I remember," Gibbs replied, simply.

"Well, Kelly wanted to read the book 'Watership Down'," Fiona went on. "And Dean, Sam and I started reading it with her and we all did voices for the characters."

"After that," Sam said, picking up the story. "Kelly called me 'Hazel' and Dean 'Bigwig'."

"And I got stuck with 'Fiver'," Fiona finished as she went into the kitchen and grabbed four beers from the fridge. Once everyone had a drink, she looked at Sam who had brought the packages Dean had dropped in the hallway and set them on the counter. "So what's with the housewarming gifts?"

Dean slid the larger box towards Fiona but didn't say anything as she opened the box and withdrew a gleaming sword.

"Dean," Fiona said, breathlessly as she lifted the US Marine Corps NCO sword and hefted it in her hands, being careful of the blade as she pulled the sword from the scabbard. "How the hell did you get this?"

"Called in a couple favors," Dean replied, vaguely as he glanced in Gibbs' direction.

Fiona caught the glance and smirked as she laid the sword down on the counter. "Gibbs knows."

"Knows…?" Sam asked, studying Fiona.

"Demons, ghosts… the whole hunter gig," she replied, sipping her beer. She looked over at Gibbs as if asking for permission to explain. When Gibbs gave her a nod, she said, "Gibbs' wife and daughter were killed almost 20 years ago."

"Wait," Sam said, setting his beer down. "I remember that." Looking at Dean, he went on. "Dad left us with Bobby for almost 5 months. We thought he was on another hunt but he said he was helping out a friend."

"John and James came by," Gibbs said, picking up the story. "Stayed until they were sure I wasn't going to… go off the deep end."

"Or eat your gun," Fiona added, giving Gibbs a look. "Dad said you really had him worried a couple times."

"Where is your dad?" Dean asked, suddenly curious. It seemed odd that James Brendan wouldn't be around when his only child was getting such a prestigious advancement in rank.

Fiona's expression grew stony as she downed the rest of her beer. "He says he's coming but I can count the number of times Dad's kept his promises on one hand."

Dean wasn't sure what to say to that since his own father hadn't been much better about keeping promises before he'd died. Sliding the smaller package towards Fiona, he said, "Well, we're here, anyway."

"And I really appreciate it," Fiona assured him. "I mean, Gibbs I knew I could count on. And there's the guys in my unit who'll be there. But you and Sam coming here… I can't thank you guys enough."

"Hey, it's the least we could do," Sam assured her with a smile.

Fiona gave him a smile before opening the second box and pulling out a USMC K-Bar knife with a deer antler handle. "Nice," she said, admiring the knife. Looking at the runes engraved on the blade, she added, "Interesting lettering."

"Yeah, a, uh… a friend helped me out with that," Dean replied. "One of two knives in the world that can kill demons."

Fiona slid the knife back into its sheath and looked at Dean and Sam. "You guys are the best." Turning to Gibbs, she gave him a kiss on the cheek. "And thank you so much for coming tomorrow."

"Hey, what kind of godfather would I be if I stood you up?" Gibbs replied, giving her a smile and a return kiss on the cheek. "Mind if I bring company in the morning?"

"Oh, please do," Fiona said with a smile. "More the merrier." Looking at the clock on the wall, she added, "Couple guys in my unit wanted to get together for dinner. You guys game?"

Dean gave Fiona his best smile. "You know me. I love a party."

"I'm in," Sam added.

"Ah, what the hell," Gibbs added. "Why not?"