This is the principal. Would the custodian please report to the faculty restroom with a plunger . . . no, wait . . . a shovel and a plunger? And has anybody seen the gerbil from room two oh six?   The Mudshark was cool.   Not because he said he was cool or knew he was or thought it. Not because he tried or even cared.   He just was.   Kind of tall, kind of thin, with a long face, brown eyes and hair and a quick smile that jumped out and went back. When he walked down a hall he didn't just walk, he seemed to move as a part of the hall. He'd suddenly appear out of nowhere, as if he'dalways been there.   Wasn't there.   Then there.   His real name was Lyle Williams and for most of his twelve-year-old life people had just called him Lyle.   But one day, when he'd been playing Death Ball--a kind of soccer mixed with football and wrestling and rugby and mudfighting, a citywide, generations-old obsession that had been banned from school property because of, according to the principal, CertainInsurance Restrictions and Prohibitions Owing to Alarming Health Risks Stemming from the Inhalation and Ingestion of Copious Amounts of Mud--he'd been tripped. Everyone thought he was down for the count, flat on his back, covered in mud. Just then, a runner-kicker-wrestler-mudfightercame too close to him, streaking downfield with the ball, and one of Lyle's hands snaked out and caught the runner by an ankle.   "So fast, it was like a mudshark," Billy Crisper said later. He always watched the animal channel. "Mudsharks lie in the mud and when something comes by, they grab it so fast that even high-speed cameras can't catch it. I didn't even see his hand move,I didn't see so much as a blur."   After that game, no one called him Lyle.   Mudshark's agility had been honed at home, courtesy of his triplet baby sisters--Kara, Sara and Tara. Once they started crawling, his father said that all heck broke loose, because nothing moves faster than a tiny, determined toddler heading toward a breakableor swallowable object. If Mudshark had only had one little sister or maybe even two, his reflexes wouldn't have been so keen, but living under the same roof as three mobile units at one time had increased his range of motion and speed exponentially.   One night after dinner when they were about seven months old, the babies had been placed on a blanket on the floor and were playing with soft toys. Mudshark was doing his homework at the desk in the corner of the family room and his parents were watchingthe news and, frankly, dozing on the couch.   Out of the corner of his eye, Mudshark saw a pink flash.   His head whipped around. Two babies were sitting on the blanket, looking toward the door to the hallway. Two, but not three. His parents were half asleep and he didn't want to disturb them. As he leapt silently to his feet and took a step toward the door,he saw two pink streaks darting past him in the same direction. Mudshark reached out and grabbed both babies by the back of their overalls as they crawled after their more adventurous sister. He scooped them up and tucked one under each arm in one fell swoop,heading out of the room toward the rogue baby.   Down the hall toward the kitchen, he saw a little rosebud-covered bottom (a quick glance at the faces he had clutched under his arms told him that Tara had made the first break) rounding the corner to the guest room. He took long strides toward her, Karaand Sara cooing at the jouncy ride. When he got to the guest room, he stared down at Tara, who had found one of the dog's squeezy toys and was happily gumming it (EEY-ah, EEY-ah . . . ). Three babies, two arms.   He shifted the two girls he was holding to his left side, sliding his arm through their overall straps as if he were slinging a backpack over his forearm. They hung there, gurgling, while he bent over and plucked Tara off the floor.   Mudshark and his wriggling crew returned to the family room, where his parents slept peacefully, unaware that the triplets had discovered mobility.   From that moment on, Mudshark did everything he could to anticipate their moves and keep them out of trouble. He stood guard between the triplets and electrical outlets (there had been a close call with Tara, a Barbie doll and a surge protector), the dogbowl (Sara was especially fond of kibble) and   the cat box (Mudshark made a flying leap across the room the first time he saw Kara sitting next to the litter box, reaching a small hand toward the mysterious clumps she saw. He snatched her up before she connected). Yes, he owed his speed and attentionto detail to Kara, Sara and Tara.   But the way he moved wasn't why Mudshark was cool.   And it wasn't his clothes. Sometimes his outfit fit in with the way everybody else dressed and sometimes it didn't. Once, he wore a green wool sweater that had a yellow leather diamond stamped with the head of a poodle in the middle of the chest. It wasas ugly as broken teeth chewing rotten meat, but by the end of the day everybody in school wished they had a green wool sweater with a yellow leather diamond and a poodle on it, too.   That's how cool Mudshark was.   It didn't matter to Mudshark what they called him or that he wasn't allowed to play Death Ball anymore because of how badly he'd frightened the other players with his fast moves (Death Ball was not known to require cunning or quickness, just the bruteforce and raw grit necessary to last the four quarters of, as parents and other adults shudderingly referred to it, That Game). Mudshark knew cool wasn't in how you moved or a name or clothes or whether or not you were asked to play on anyone's team.   It was all in the way your thoughts ran through your mind, the way you managed the flow of electrical charges jumping from one brain cell to another to form ideas.   That's what makes somebody who they are. And that's why Mudshark was so cool.   He thought.   While everyone else was hanging out or goofing off or playing video games or listening to music or watching TV or walking down the hallway in a funk or texting each other or surfing the Net, he was observing the people and objects and sights and scenesaround him.   Thinking.   Once, when he was just five and a half years old, he went up to his mother and said:   "Mom, I think all the time."   "About what?"   "Everything." Deep breath, let it out, sigh.   "What are you thinking about right now?"   "Fingernails grow exactly four times faster than toenails, but it's not like we need toenails because we don't even use them for scratching and did you know that an octopus doesn't even have toenails . . ." He sighed again, and as he turned to walk away,he said, "It makes a man think."   He also read all the time. His mother was the lead research coordinator at the public library, and from the time he was very tiny, she'd brought him to work with her, setting him on the floor behind her desk with a stack of books she'd absentmindedly pulledfrom the nearest shelf--never picture books or easy readers, but books on astronomy and astrophysics and the history of democracy and the rise and fall of ancient civilizations. He'd learned to read before he went to kindergarten and was always carrying twoor three books with him. He only had to read a page once to be able to quote from it word for word.   As he grew older, his memory became better because of the way he learned to pay attention to every sight, smell, taste and sound every minute of every day. As with any skill, practice made him more proficient, and over time, he'd developed a nearly photographicmemory.   Eventually people noticed his knack for quoting obscure facts and remembering tiny details, and when a kid at school had a question or problem, someone would say "Ask Mudshark."   "Hey, Mudshark," Markie McCorkin said, "I lost my homework!"   And Mudshark remembered him sitting by the steps in front of the school where two small kids had been playing with a ball, a yellow ball, that they'd thrown in the bushes back of where Markie sat. One of them had accidentally kicked Markie's orange folderso that his homework papers, held together with a red paper clip, fell out of the folder while he was telling Todd DeClouet about the new tires on his bicycle and how well they gripped in dirt, although not as well as he'd thought they might.   And Markie ran to the front bushes and sure enough, his homework was there. Exactly where Mudshark had said it would be.