(A/N: This is a very random AU idea where the musketeers are a modern crime investigative team. I've not tried anything like this before; I hope you enjoy it!)

"You can't be serious."

D'Artagnan stared. His confusion was almost a mirror of Aramis', except that his colleague's bemusement was the result of disbelief, rather than a total lack of understanding of what was going on.

"About... what?" d'Artagnan asked, raising his eyebrows at Porthos, who was lurking in the doorway. There was no help to be found from that quarter, though, as the man simply shook his head. Was that a gesture of solidarity in the face of Aramis' oddities, or did Porthos know something he didn't?

Aramis threw his hands wildly into the air before plucking the fourth cup out of the cardboard container in d'Artagnan's hands.

"This!"

"That's a cup of coffee."

"Exactly!"

Still nothing from Porthos, who d'Artagnan began to suspect was being deliberately oblivious to his attempts to non-verbally request an evac. Aramis was still staring at him like he was insane.

"It's a cup of coffee," d'Artagnan repeated slowly, exaggerating the words. "From that nice little place in the next street, your favourite, right? Since we've all been dragged in early on a Saturday for this case, I figured you might like some coffee. Apparently that means I've kick-started the apocalypse, so I guess I should apologise for that."

Finally, Porthos cracked a smile, but Aramis gave a loud cry in Spanish, of which the only word d'Artagnan could pick out was 'God'. He then flung an arm round d'Artagnan's shoulders - luckily the one that wasn't holding the offending cup.

"Oh, d'Artagnan, my brother! I know you're new here-"

"It's been three months, Aramis."

"-and you're barely more than a child-"

"I'm twenty four, Aramis, and only five years younger than you."

"-but there are some things you must understand about the world! You can't give that to Athos."

"Why, is he lactose intolerant?"

Porthos was now definitely chuckling quietly, though d'Artagnan had given up trying to make eye contact and had no idea which one of them was amusing him. Knowing full well Aramis would follow, d'Artagnan dodged round him and into the office. It was empty apart from them, occupied only by gently humming computers. Ah, the manifold joys of being on call. He wasn't sure what the situation was, but given that Athos wasn't there bringing the errant members of the team into line, the case they'd been brought in for couldn't be too urgent.

He deposited a cup on Porthos' desk and one on his own, but when he turned round again Aramis had snuck up perilously close.

"Of course not, my dear Gascon! But there are some things you only learn about our mysterious leader when you've been here some time. It took me at least five months to learn how to survive under his rule."

"Treville's not that bad," d'Artagnan said, smothering his own grin as Aramis gave him a look of despair.

"Not Treville - Athos! He's a dangerous creature, especially in the morning, especially on weekends. He drinks enough at the best of times but Friday night's basically being given permission. He has very refined tastes. Athos doesn't drink coffee. It's tea, always. Earl grey, teabag steeped for precisely two minutes, and a dash of milk added after - it must be after. Anything else is basically sacrilege. If you give him coffee, this day is going to be hell."

"Which is why you're confiscating it?"

"Precisely! You'd better give me the other one too, so he doesn't realise."

"I don't think you need any caffeine at all," d'Artagnan said, looking at him warily. "How are you this exuberant? It's way too early for me to have to deal with you."

"Don't look at me," Porthos said, forestalling d'Artagnan's next effort for rescue. "I had three years of being the only one who had to put up with him, ain't like Athos is a lot of help. S'your turn now."

D'Artagnan glared, regretting that he'd already given Porthos his drink and therefore lacked any bartering chips; the other man had already crashed in his desk chair and was contentedly sipping the coffee as he watched the show.

"Jealousy is unbecoming of you both," Aramis announced, sitting himself with frustrating grace on the edge of d'Artagnan's desk. "I have learned things few others know about our boss through careful investigation."

"So what you're saying," d'Artagnan said thoughtfully, "is that it takes someone with investigative skills far beyond his colleagues' to learn how Athos takes his drinks in the first five months of working with him?"

He was deliberately avoiding looking at either of them, but he could feel Porthos' eyes on him. Aramis was audibly delighted with his answer.

"Indeed! It took months of tracing his habits and enquiring around to discover the truth without raising his suspicions. It's proof of how much I like you that I'm willing to tell you the secret, by the way. I let Porthos get it wrong for a year. The boss'll be very impressed next time. For now, I suggest you hide that other cup before - good morning, Athos!"

D'Artagnan turned just as Athos rounded the corner. Like Aramis, he looked annoyingly immaculate despite the early hour (d'Artagnan's hair was still damp from his shower and his jacket was wrinkled from having been tossed on the floor the night before), but he at least had the decency to be speak quietly.

"Apologies for your lost weekend, gentlemen. We're due in Treville's office in five for the briefing."

Ignoring Aramis' painful lack of subtlety as he flapped his hands wildly, d'Artagnan handed the fourth cup over to Athos without a word before retreating to his own chair. He took a long draft of his own coffee (a very pleasant mocha) as he logged on to check his emails before the meeting. Aramis was still perched on his desk, which meant d'Artagnan had a very good seat to the moment when he first took a mouthful of the pilfered coffee.

It was a good moment. His mouth curved into an involuntary smile, before his eyes widened - the first signs of misgiving because of the flavour of his coffee (milky, with hazelnut syrup). Aramis' favourite, which meant he hadn't taken the cup intended for Athos.

Still pretending to be looking at his screen, d'Artagnan watched Aramis' gaze flick over to Porthos, who was already draining his cup (vanilla with extra cream) with a pleased expression.

Slowly, Aramis' head turned to Athos, who was checking through a file on his desk and, without looking, taking a drink.

Was Aramis actually holding his breath? Maybe he was waiting for the explosion, but he definitely suspected something already - and, when it came, Athos' reaction was so slight they might have missed it if they weren't watching.

A small sigh, and a twitch at the corner of his mouth. In anyone else, it would have been called a smile; Athos actually looked contented.

A phone rang; Athos picked up the receiver, listened briefly, then replaced it and nodded to the others. "We're up."

D'Artagnan made to follow as their boss led the way towards the corridor, but Aramis blocked his path. "How did you do that?"

He affected his most innocent expression. "Do what?"

"You got his drink right! I've seen Athos tear people a new one for as little as putting sugar in his tea, so you must have got it right, but-"

"The kid's good," Porthos said, clapping Aramis consolingly on the back, but the grin he gave d'Artagnan was rather more knowing than his words suggested. "Guess you can't win 'em all, buddy."

"But - but-"

"I suppose this means I've exceeded you already," d'Artagnan said with a broad, unreservedly smug grin, as Aramis stared at him in horror. "And to think it took you five whole months. Terrible, really."

Leaving Aramis standing there, stunned and speechless, d'Artagnan hurried after Athos, beaming all the way. Now that was a good way to start the weekend.

He'd have to delete the text as quickly as possible, of course. It wouldn't do for Aramis to see the message he'd received half an hour before.

Tea for me, actually, earl grey - 2 min brew, dash of milk. Thanks, d'Artagnan.

Technically, it might be cheating - but when you had three brothers to contend with, there was no such thing as playing fair.