AS IT NEVER WOULD BE after classes started, the whole school was open to us when we prowled it in secret.  From any point of view other than ours, I suppose, it was closed to us, but because all its parts were equally closed, once we had penetrated one barrier we had penetrated them all.  We prowled everywhere, visited every classroom, explored the machinery rooms, knew every closet and storage room, poked around in every office.  As the end of the summer approached, we began to resent the fact that we were going to lose our exclusive relationship with the building.
    On one of our nighttime visits, we discovered that the entry hall had been laid with terrazzo, the flooring material most like life.  To make a terrazzo floor, chips of marble are scattered in a soup of cement, like notable moments scattered through a life, and then, when the conglomerate hardens, the surface is polished so that the bright chips show to good advantage, glinting against the monotonous ground as notable moments do in the memory.  We knew that on the first day of school a train of buses would discharge students into this terrazzo entry, so we wanted to lay claim to it, to walk all over it, cover it as thoroughly as we could, make certain that we would be the first kids ever to step on any part of it, mark it as our own before the mob got to it. 
    We walked, we marched, we hopped, we skated, and my mind began to wander in a direction that had become habitual—toward Raskol’s sister, Ariane.  She was on my mind more and more often.  When I say that she was on my mind, I mean not only that I pictured her or heard her voice or cast her as the female lead in certain fantasies, though I did all of that, but there was something else, too, an accompaniment to these thoughts of her, something like the background music in a film, but an accompaniment for all the senses, a set of sensations that I cannot fully recall or describe, but which, it seems to me, resembled smoke, Scotch, silk, and saxophones.  (This can’t be true, since I hadn’t tasted Scotch at the time, but it’s as accurate as I can make it now, at the time of writing.)  As a result, I had begun to feel awkward in Raskol’s company.  My awkwardness resulted not only from the fact that I was preoccupied with his sister, but from my unsettling discovery that the mere sight of him made me think of her, made the light seem to dim, summoned the aroma of smoke, the taste of Scotch, the brush of silk, a saxophone’s moan.
    I had drifted into one of my reveries of Ariane while we were gliding around on the terrazzo.  This one involved my being in that very building, that very night, alone with her instead of Raskol.  Ariane and I had been wandering around the building hand in hand and had come to an open window where the night breeze drifted in, bringing with it the pale moonlight.  Standing there, dreamy-eyed, Ariane idly fingered the buttons of her blouse.  One slipped open, then another, and—
    “Damn!” said Raskol.
    “What?” I said, or squeaked.  Caught!  Some look must have betrayed my desires.  It wouldn’t have surprised me if Raskol had said, “Damn it, Peter, button my sister’s blouse back up—right now, this minute.”
    Instead he said, “Look at that,” nodding back at where we’d been.  I saw, in a slant of moonlight much like the one that had illuminated Ariane, footprints of terrazzo dust.  Before, in the dark, we hadn’t realized that a dusty residue from the polishing remained on the surface.  Now we were tracking it through the school.
    “Oh,” I said, relieved.  “That.  Well.  That’s nothing.”
    “Nothing?” he said.  “It’s evidence.  And we don’t want anyone to know we’ve been here.”
    “Oh.  Sure.  That’s right.”
    “Peter,” he said.  “Wake up.  Snap out of it.  You’ve been in another world.  You know that?”
    “Huh?  Oh.  You mean the way I kind of drifted off?  I can explain that—”
    “It started while we were skating around on the terrazzo.  You seemed to skate off into—some other place.”
    “Yeah.  Well.  It’s funny you should mention that—”
    “I think I know what it is,” he said.  “What makes you drift off like that.”
    “You do?”
    “Sure,” he said.  “It’s that imagination of yours.  Your head’s in the clouds.  Not just in the clouds—in outer space.”
    “Heh-heh-heh.  I guess you caught me,” said I, relieved to find that apparently he hadn’t.
    “You were probably thinking about—”  Or had he?
    “Look, I can explain, Raskol—” I said.
    “The moon, right?” he guessed.
    “Well, look,” I said, still in the confessional mode, “I—”
    “And Mars?”
    “What?” I asked, beginning to wake up.
    “And the stars,” he said, “and—the whole universe.”
    “Gosh,” I said, truly amazed.  “I mean—that’s right.  Exactly right.  How did you figure that out?”
    “Easy,” he said.  “It was the moon that got you going.  On the way over here.  The full moon.”
    “Amazing,” I said.
    “Hey, I know how your mind works,” he claimed.  “One little thing gets you going, and you’re off on a train of thought that makes lots of stops.  Any little station that comes along—you’re liable to get off and take the next train that comes through.  No telling where you’ll wind up.  You’ve got a strange mind.”
    I thought it might be best to say nothing at all about this conclusion, though I was relieved that Raskol didn’t know my mind as well as he thought, and I was flattered to have him think that I had a strange mind.  It was a good time to change the subject.
    “We can wipe up the footprints with our shirts,” I said.
    “Yeah, but that’s only part of the problem,” said Raskol.  “We’ve left our footsteps in the dust on the terrazzo.  We’re going to have to put it back the way it was.”
    “What?”
    “We’re going to have to rearrange the dust,” he said.
    We returned to the entry, got down on our hands and knees, and, using our hands and puffs of breath, spread the dust around in a good imitation of its condition when we had arrived.  Terrazzo dust is a demanding medium, fine and unforgiving, choking and dirty.  I hope I never have to work in it again.
    That left our footprints, extending down the hall.  When we had finished wiping them up with our shirts, I was ready to call it a night and go home, but Raskol had noticed something new; “Hey,” he said.  “Look at those tags.”
    Looking down the corridor, I saw yellow tags attached to each locker, folded flaps of paper, like butterflies that had lighted there.  I got up, pinched one, and opened it.  On it was printed the combination of the lock that had been installed in the door.
    “Hey,” said Raskol from the other side of the hallway.  “You see what’s on these tags?”
    “Yeah,” I said.  “The combinations.”
    He thought for a minute.  “You got any paper with you?” he asked.
    “Sure,” I said.  In those days I always carried a small wirebound notebook.
    “Copy these combinations, okay?”
    “All of them?”
    “Yeah, all of them.  Better get them all.”
    “That’s going to take some time.”
    “Okay, we’ll do them in shifts.  You go on and get some, and when you get tired come back here and I’ll take over.  Be sure to write down the number of the locker, too.”
    “Okay,” I said.
    I wandered through the school for a while, jotting down locker combinations until I felt I’d done my share.  When I got back to Raskol, he had one of the locks apart.
    “And look at this,” he said, as if I’d been standing beside him all along.  “Just two bolts hold these locks in the door.  See?  You can take one off in a few seconds—if you’ve got the door open.  Now watch this.  This little cap with the numbers printed on it fits onto this shaft and over the splines.”
    Splines.  What a nice word.  This was my first encounter with it.  It appealed to me at once.  It seemed inherently poetic, sensual.  In fact, it sounded so good that I could imagine lots of uses for it, none of which was related to combination locks.  Splines could be soft, round, benign creatures, handy to writers as emblems of hope and calm: “When the storm abated at last, Cynthia and I emerged from the cave where we’d sought shelter.  A preternatural calm had settled over the sea, and the splines had come out to sun themselves on the rocks.”  Just as easily, they could be the sort of rich, comforting food that grandmothers specialized in: “Jimmy!  Time to get up now, you hear?  Grandma has fixed you your favorite—hot splines with butter and honey.”  My ignorance of the true nature of splines must have shown, since Raskol went on to deliver an explanation.
    “See these little slots inside the cap?” he said.  “They slide onto these ridges on the shaft.  Those are the splines.  They make the cap turn the shaft instead of just turning on it.”
    Ah, splines.  What a good idea.  What a nice word.  The idea of a splined shaft appealed to me almost as much as the word.  As a device, it demonstrated economy of design.  As a concept, it suggested security.  Spline still sounds wonderful to me.  That moment in the empty school building when I first heard the word has stood out in my memory ever since, and it gives me great pleasure now to brush aside the dust of the intervening years and let this bright chip shine.
    “I see,” I said, and I wanted to add that I’d seen splines before, on the shaft of the windup record player, but Raskol rushed on.
    “Well, get this,” he said.  “There’s a little mark here on the shaft that shows where zero is supposed to line up.  See?”
    “Yep.”
    “But—when I put the cap back—if I turn it so that it goes onto the shaft just one spline out of line—like this—see what happens?”
    “Yeah,” I said.  “The five is where the zero is supposed to be.”
    He just stood there grinning.
    “How long do you suppose it would take to change them all?” I asked.
    “Not long,” he said.  “But that’s not what I want to do.  Not now.”
    This surprised me.  It seemed like a great stunt, the sort of thing that would make us famous.
    “Words of wisdom from my father,” said Raskol.  “Keep an ace in the hole.  A dollar in your pocket.  Never let them know all you know.”  I knew that he really did follow this last bit of advice.  He was wary about letting the teachers know how much he knew.  He always suspected their motives when they questioned him.
    “This,” he said, reassembling the lock, “is something to keep up our sleeves.”