"I don't see why it has to be an actual party, that's all," Casey muttered with the annoying whine of a spoiled four-year-old.

"Come on, Casey, it'll be fun, you'll see!"

Chuck probably wasn't helping matters, as far as Sarah could tell, by being so cheerful and upbeat, especially when, as Chuck's smile got wider and brighter, Casey's scowl got deeper and darker. And, frankly, even Chuck should know by now that a friendly pat on Casey's back was a mistake under any circumstances, so the look of shocked surprise Chuck shot her when the big man's arm darted out like an uncoiling cobra and his fingers began tightening around Chuck's throat, in Sarah's estimation, was completely uncalled for.

Sarah slammed both palms down on the conference table in Castle.

"You two! Stop it right now!" she commanded, glaring at them both.

Now the men each had funny looks on their faces – hand-in-the-cookie-jar, jam-on-the-lips, eye-to-the-peephole looks – except Chuck's face was a bit pinker than Casey's due to lack of oxygen.

Sarah whipped a handgun out from behind her back and pointed it at Casey's head, shouting, "Drop it, Casey! Drop it now!"

Casey obliged by loosening his grip on the Intersect then hiding his hands behind his back guiltily and putting on his best innocent choirboy face. Chuck wasn't badly injured, but he figured since Sarah didn't know that, a bit of extra gasping and neck rubbing wouldn't hurt, and he set about it industriously.

"Good boy, Casey," Sarah commented as she re-holstered her gun and turned back to the file folder she had prepared that was lying open on the tabletop.

"Now," she commenced in a businesslike tone, "let's see if we've overlooked any details here. Casey's cover birthday party needs to be just perfect."

Sarah and Casey were tidying up in Castle prior to heading over to Chuck's place for the cover birthday party. As Casey finished counting the last of the small handguns and strapping them into their holders in the large wall cabinet, Sarah repaired her make-up in a compact mirror that could double as a camera, a digital audio recorder, a GPS tracking monitor or a soporific injector. And it also had a nice assortment of foundation and blush, some of which Sarah swooshed over her cheeks with a flourish.

Casey hadn't stopped complaining all day and Sarah, frankly, was tired of it.

"I wish you'd just ship me off to Iraq," he said to her loudly. "At least there I'd have half a chance."

"Oh, Casey, stop being so dramatic," Sarah said as she snapped her compact closed and put it in her purse. "It's just a little party. And who knows? You might actually have some fun."

Sarah paused and smiled before standing up and looking in her partner's direction.

"That is, if you know how to have fun," she said as she started up the stairs to Orange Orange.

"Ha, ha, Walker," Casey replied sarcastically. "I know how to have fun. I just need an F-18 to do it, that's all."

When they neared the entrance to Chuck's and Casey's apartment complex, Sarah pulled Casey to one side.

"Don't forget," she said, "act surprised. It'll make Ellie happy. And I think they're going to hide and jump out at you anyway. It's what normal people do. Try acting surprised now."

Casey grimaced, then scowled, then essayed a smile that looked to Sarah a bit like a rictus of death. Since she supposed it was too late to do anything about it, she smiled at him and reached up to straighten the shoulder seams of his shirt, neatly stepping back to avoid his arm as he reflexively tried to shoo her away.

"Let's get it over with," he snarled and turned to march resolutely down the alley as though he were going to the electric chair.

When Casey and Sarah came out from the arched alleyway and into the complex's courtyard, all was quiet and normal for a Saturday evening, but when they reached the midpoint, just on the far side of the central fountain, several people, including Chuck, Ellie, Captain Awesome, quite a few Buy More employees, and three attractive women, jumped out from hiding places, yelling, "Surprise!" and "Happy Birthday!"

As it turned out, Sarah was the one suitably surprised. Casey's reaction looked genuine enough as he smiled broadly and exclaimed breathlessly, palm on his chest, "Oh, you scared me! Oh, everybody, this is so great! Thank you all!"

As Sarah skirted around him to go and greet Ellie, she whispered in a low hiss, "Don't overdo it," then smiled and held her arms out for a hug from Chuck's older sister.

Casey, meanwhile, was busy fielding all the offers of handshakes from the men and hugs from the women – well, and one offer of a hug from Jeff, which the agent warded off with a nasty glare – when he felt something cold and wet shoved into his hand. Chuck was beside him and had provided a chilled brew. The Intersect then took Casey by one elbow and steered the fake birthday boy over towards the three women he had seen when he had come in. Upon closer inspection, they were even more interesting than from a distance, and Casey displayed his most charming, most dazzling smile, which immediately had the desired effect.

The tidal surge almost knocked Chuck from his feet as the women crowded around closely, each trying to draw their quarry's attention away from the other two by a flurry of fluttering eyelids, artfully displayed cleavage and fingertips lightly brushing Casey's forearms amid girlish giggles and simpers.

"Ladies, this is John Casey, our neighbor. John, these are doctor friends of Ellie's from the hospital. Ellie thought you might like to meet them," Chuck said, noticing that Casey wasn't really paying him too much attention at this point.

"Well, thanks for coming to my party," Casey rumbled in a Barry White bass perfected during his three rounds of Infiltration and Inducement of Enemy Personnel classes with Roan Montgomery. "Which of you is going to help me with my frosting?"

Chuck, after taking a moment to admire the top agent's adaptability and commitment to his mission and cover, joined Sarah near the fountain.

"Looks like the major is going to have fun after all," he said to the blonde agent, who handed him a bottle of beer. "You've done it again, Sarah."

Sarah glanced up at Chuck and grinned. "It wasn't that hard to figure out, you know. After all, underneath all that spy training, Casey is still just a guy."