A/N: Be warned; there are a lot of technical terms in this one. I tried not to use them unnecessarily, and I tried to define them all as close to their use as possible. The idea for this one came to me and would NOT let me go because, yes, I have played this sport, and yes I think it is something Marshall would enjoy, kick all kinds of backside at, and look so good doing that it would probably cause heart palpitations.

Spoilers? Ain't any. This is a universe all its own.

Warnings? Language, language, language. Boy, does Mary need to watch that stuff! Oh, and if you get far enough, beware of the citrus. Citrus will be flying all around. This is my first attempt at writing smut, just to see if I can. I'll tag that chapter with a citrus warning.

Disclaimers? I don't own them. Otherwise I would tuck Marshall in my pocket and keep him for my very own.

Had the weather not been unseasonably warm, the whole thing probably never would have happened. They were sitting in the GMC on a stakeout, though, and what had been predicted as a coolish spring day had heated up to a ridiculous degree with a humidity that Albuquerque almost never had. Mary and Marshall had shed jackets hours ago and the slight breeze through the rolled-down windows was far too stingy to cool them.

Mary shifted restlessly. "It's hotter than nine hells in here," she muttered. "Why is the weather always absolute shit for stakeouts? Why, just once, just for giggles, couldn't we get a stakeout where it was cool with a light breeze, zero humidity, no snow, no rain of blood falling from the sky..."

Marshall didn't turn the binoculars away from the window. "Fire. Rain of fire. Actually fire intermixed with hail. The blood was in the Nile, which was a double-whammy to the ancient Egyptians since they considered the river divine," he said absently.

Even for Marshall, that had been random. Heat had reduced her normal tolerance for everything which was never very great to less than nothing. "Marshall, what the fuck? Are you suffering from dehydration? Do I need to call a bus? Officer down?"

Marshall's mouth quirked up at the corners, but he still didn't lower the binoculars. "Come on, Mare... you were talking about the Plagues of Egypt weren't you? It was a rain of fire, not blood. The waters of Egypt turning to blood was the first plague that happened, then came the frogs, then the flies or gnats, there is disagreement about the exact translation of that word...."

"Stop it. Stop right there, or there will be a rain of blood in this car as I pummel you unconscious. I cannot take Biblical trivia in all this heat." She fidgeted another moment. "Give me those damn binoculars. I'll take over. Give me something to do other than melt into a puddle. See if you can get a little bit of a nap or something. Apparently these assholes are going to take their time about this. We might be out in this heat all day." And if we are, somebody is going to pay....

Marshall handed them over with a small sigh and stretched his long arms out in front of him, fingers laced so the joints popped. He leaned the seat back and closed his eyes. A moment later, eyes still closed, he undid the cuff buttons of his long-sleeved shirt and rolled them up in an effort to cool off a little. The motion caught Mary's eye and that's when she saw the enormous bruises covering Marshall's right forearm like an Impressionist canvas in black, blue, and purple. No mere bump could have caused those, and Mary could think of no encounter during the past two abnormally-peaceful weeks of WITSEC activity that would account for the livid blotches of color on her partner's arm.

"Jesus, Marshall, what have you done to yourself?" she asked, lowering the binoculars. She trailed light fingertips across the bruise reflexively as Marshall's eyes opened, just a little wary and startled. Wasn't expecting me to touch him....

"What? Oh...that. Yeah." He sank back on the seat with an amused smile, and looked at the patches on his forearm himself. "It's fine. They don't really hurt anymore. They just look bad. I had forgotten all about them."

"I'm striving for patience here, genius. What caused them?"

Marshall turned his head to look more fully at her and said with his most irritating smile, "Why do you want to know?"

Mary bared her teeth, but what she was giving him probably wouldn't have been called a smile by most sane people. "Maybe it's because I'm bored. Maybe it's because I'm curious. Maybe it's because I'm looking for pointers before I proceed to put similar marks all over your body because you're pissing me off by not answering my questions."

Marshall, knowing her well, was unmoved, and he laughed at her.

"Three seconds, Marshall. Three seconds, and I'm going to take my hands, apply them to those bruises and make you sing..."

Marshall crooked his eyebrow with mischief dancing in his eyes, tilted his chin, and lowered his voice, "Mare, you can apply your hands to any part of me any time you'd like, but gently, gently..."

Mary laughed, despite the heat. "Pervert. You probably like it rough, anyway. I bet that's where those damn bruises came from."

"Aahh, but Maare," Marshall crooned with the wickedest of his grins, "you know I only like it rough if it comes from you." There was no space in the GMC cab to elude the punch she gave him even though he knew it was coming, but since he was laughing like a crazy person when it landed, Mary could only assume it hadn't hurt him too much. When his laughter subsided, he looked up at her with those still-amused blue eyes and said, "No, in all seriousness, I got these from some people who have no idea how to control themselves when they attempt migi-kote-uchi."

What the fuck? "And that would be what exactly? Some kind of Japanese geek group sex maneuver you found online?"

His lips quirked briefly. "Nope. That's kendo."

"Keep in mind that I've been sitting in this damn vehicular sauna for five hours already, and just give me the Readers' Digest version, please."

"Kendo means 'the Way of the Sword.' It's one of Japan's oldest martial arts and it has its roots in Bushido, the 'Way of the Samurai.' Most scholars argue that it really got its start as a separate martial art during the Edo Period..." Marshall saw Mary's eyes begin to take on that glazed look, and he edited down his trivia hurriedly so as not to lose her... "but basically it is a descendant of the samurai's practice with the long sword and the mental and physical disciplines associated with it."

"And you do this. You go dress up somewhere and swing samurai swords about in your spare time."

"Yep. Well, shinai or the occasional bokken, but yeah, basically. Have for years."

Mary looked at Marshall through narrowed eyes. How could she not know something like this about her partner? Was this odd, or was this just....Marshall? Marshall was still sprawled on the seat simply looking back at her. She could not reconcile her geeky, pun-making partner with what she commonly thought of when the idea of samurai came to her mind. The two images just would not go together, except in ways that led to laughter.... Marshall in a kimono, Marshall with his head shaved. Marshall talking except his words did not match the motion of his mouth....

"And would this be something a person could come and watch, or does this take place in some secret ninja enclave high in the hills somewhere?" said Mary with a totally earnest expression, waving her hand idly at the open window.

"I guess I could probably sneak you into the cave and hide you behind an outcropping of rocks if you promised you'd be really quiet," he said, equally deadpan. About that time there was movement from the house they were watching, and both of them snapped to alertness....