Author's note: After a long break from writing, I started on this idea and could not get it to go where I wanted it to! So, here's what did happen, which is different from my usual action/adventure fare, but perhaps will be worth a moment of two of entertainment!

Flashback 3 years ago: In the Void, returning to the Pegasus Galaxy on Board the Deadalus just after the siege of Atlantis

"It's a nine."

"I agree that most probably the nine goes there, but you need to prove that all other options – "

"McKay. It's a nine."

"You haven't checked against the other columns-"

"Just write the damn nine down in the box, McKay!"

Rodney tossed the pencil back and folded his arms across his chest. Sheppard snatched for it and scribbled a nine into the square in question, then flicked the pencil over several other boxes, jotting down other numbers in a seemingly random pattern. Rodney sighed, giving up on trying to teach Sheppard anything about proper methodology for solving the ridiculously inane Sudoku puzzles.

Instead, Rodney stretched and looked around the Deadalus' common room, noticing how many of the off duty crew and passengers were also scribbling over collections of Sudoku. The members of the Atlantis expedition seemed particularly interested in catching up with the trend that had caught on during their year-long separation from Earth. Rodney had found the first two or three he'd solved amusing. After that, it had become simple execution of logic, and he'd lost interest.

"See. It was a nine." Sheppard smacked the pencil down on the tabletop and lounged back into his chair, a smirk on his relaxed face.

Unable to resist, Rodney picked up the solved puzzle and checked it over for mistakes. He carefully concealed his surprise when he realized that not only was the puzzle solved correctly, but was also one of the toughest in the book.

"Yes. It all looks correct. Although how you solved all of it without a shred of proof behind your guesses is beyond me."

"I wasn't guessing." Sheppard sounded just a bit hurt by the accusation. Rodney only snorted.

"Then how did you figure the nine?" From his earlier look at the puzzle, Rodney knew that particular box could have only been deduced by a rather complicated bit of logic that he was sure was quite beyond Sheppard.

"I just knew it was a nine."

"You guessed."

"No. I knew."

"Yes, but how did you know?"

Sheppard just shrugged and grinned an infuriating grin. "That, I couldn't tell you. I just knew. Something about how the patterns were bearing out just seemed to point at the nine. The rest fell into place after that."

Rodney frowned. Sheppard had a disturbing habit of surprising Rodney with more intelligence than he gave the Air Force pilot credit for. But even given past revelations, Rodney could not quite bring himself to believe that the man had used x-wing logic intuitively. He decided to take another approach.

"'You just knew' is hardly a dependable strategy. What happens if you guess wrong, Major?"

"I didn't guess. And it's Lieutenant Colonel, now. Remember that."

"Yes, yes. But evenLieutenant Colonels make mistakes. Your method has great potential for exacerbating an error to the point of insolvability."

Sheppard blinked. "Say what?"

Rodney waved his hands in the air, "You don't check for proof as you go. If you do make a mistake, it could prove fatal."

Sheppard just stared. "It's a PUZZLE, McKay," he said.

An instant later, the ship's intercom buzzed. "Colonel Sheppard. Report to Colonel Caldwell on the bridge. Colonel Sheppard…"

"Gotta go. Do me a favor, put my book on my bunk for me."

Sheppard slid the Sudoku book over in front of Rodney, then walked briskly out of the common room. Rodney thumped the table with the book for a moment before curiosity got the best of him. He thumbed through the book looking for the puzzles that Sheppard had already solved. Now that he thought about it, he was surprised that Sheppard did puzzles at all. He seemed more the comic and coloring book type to Rodney.

Nearly half the pages were finished. Even more surprisingly, Sheppard had skipped over the easy pages in favor of the hardest. Rodney looked closer. He flipped page after page. As far as Rodney could tell, every solution was correct. The man had finished dozens of them accurately.

When had he had time to do them all? The Daedalus had been underway for a week into their two week long return trip to Atlantis. Despite Sheppard's frequent complaints about the long trip, Rodney knew that they'd been keeping him pretty busy. Something about formalizing his command on Atlantis and reorganizing the military base.

Rodney flipped faster, then finally paused on a page that seemed to have given Sheppard some trouble. Many of the boxes were smudged with erasing, the previous number, sometimes two numbers, still slightly visible under the final answer.

"Even Lt. Colonel's make mistakes," he muttered happily. He held the book closer and squinted at the layers of corrections. From what he could make out, Sheppard had done exactly as Rodney had warned him about. A problem early on had thrown off several other answers in a ripple effect of errors. Most people he'd seen working the puzzles would give up and start a new one at that point. But not Sheppard.

Rodney looked closer and realized that the man had painstakingly retraced every number, erasing and redoing, until he'd found the initial mistake. The final answers, those written on top of layers of wasted effort, were correct.

He closed the book and sat back in his chair, his arms folded over his chest again. For Rodney, watching how someone solved problems – or in this case, puzzles – was a valuable insight into that person. He'd spent the past year with Sheppard, battling the Wraith, Kolya, even killer hurricanes. Rodney grudgingly admitted that the newly christened Colonel had earned his promotion, and had even earned Rodney's respect in the way he reserved for those of limited but necessary use to him.

But Sheppard was reckless. His brash approach to the puzzles simply proved what Rodney had observed about the man so far.

"I thought you should know, the first round was a draw." No surprises there.

"Hit me with the defibrillator." Typical.

"So long, Rodney."

Rodney scrubbed his eyes, shakily, shoving aside the all-too-fresh memories of watching Sheppard fly a nuclear bomb into the belly of the hive ship. "I'm going in."

"I am too," Rodney announced to himself, pushing back his chair and rising. "Even brilliant scientists need sleep, too." He palmed the sudoku book, then left the common room. Sheppard's bunk was on the way to his own.

A few minutes later he threw the puzzles onto Sheppard's bed, stumbled the two doors down to his own. He sank onto the mattress and leaned over to tug off his boots, still thinking about Sheppard and puzzles. Now that they had a ZPM and a second chance on Atlantis, Rodney would have to keep an even closer eye on things. He was beginning to realize that it would probably fall to him to keep Sheppard out of even more trouble than he'd managed so far. Everyone else seemed smitten with the man. Only Rodney saw him for the loose cannon that he was, however brave and charming.

And as for friendship? Well, that was definitely out of the question. Men like Sheppard didn't make for good friends, Rodney decided firmly. Why take the chance of getting acquainted only to have to watch the man fly off on another suicide mission? No, he was stuck with Sheppard as military commander of Atlantis, and leader of his 'gate team. But it didn't take x-wing logic to figure out that one of these days, Sheppard would take a chance he couldn't recover from.

Rodney didn't intend to lose a friend when that happened.