So that night, wearily from his bench in Gov-Park, Jason looked up at Friday the 13th's full moon swimming amiably through its own reflected night-brightness. His brain, tired of its everlasting shuttle between worries, presented him with a disconnected memory-fact: "As cited by Zollner," Jason found himself quoting a forgotten textbook, "the Moon's reflectivity is point one seven four ... Nuts!" Angrily, he broke off, thumbed the b.u.t.ton of his communico, growled into the microphone on his lapel, "Report."

"Adams," came promptly back. "West Entry. Nothing."

"McGillis. Patrolling rear wall. All clear in both directions as far as I can see. An' I can see both ends of the Fane in all this moonlight, Chief."

"Holland. At Raichi House. Nothing."

"Johnson. East Entry. More of the same." Then, "Say, Jase, how about it?

These double shifts are getting me."

"What's the matter with you, now?"

"My feet hurt, Jase. Neither one of us is as young as we used to be, remember. How about knocking off?"

"Hmphf ..." Johnson, Jason thought, was getting old. He'd been a good man in his day but-- Hey, he was still a good man! It was Jason's own stubbornness that was wearing Johnson down. Jason's useless stubbornness. After all, without the backing of Anx or Gov, without results from the equipment he had filched to use on Lonnie, what was the use of everlastingly sticking around the Tiara like a fly buzzing mola.s.so-saccharine anyway? Jason opened his mouth to send them all home, pressed the communico b.u.t.ton and--shelved the relieving order temporarily. Instead, he blasted into the microphone: "Sergeant!

SERGEANT!"

From the communico, an intermittent drone became a gasping gulp; changed into a violent yawn and only then turned into startled speech. "Yeah?

Huh?... Yeah, Chief!"

"Sergeant, if I ever catch you asleep again, you won't ever get your pension."

"Chief, I wasn't asleep! Honest! I--"

"All right. What's happening up there?"

"Nothin' ... nothin' ... I wasn't asleep, Chief. I'd'a called you 'f anything--"

Something bright, or was it dull, plucked at the edge of Jason's vision.

Inside the Fane, far down at one end. A thin, vertical bar of difference in the blaze of light. Chin half turned, Jason stared. What?...

"_Chief!_ That tracer's asleep--I mean--that there tracer's just GONE t'sleep! I mean--Chief! It's--"

"Shut up!" Jason hissed. "Holland! If you've let anyone slip past you out of that house--"

"n.o.body did. You know me better than that, Chief."

"Adams! McGillis! Johnson! What's happening?"

"Nothing ..."

"Not a thing ..."

"_Johnson!_" Jason licked suddenly dry lips. "Dammit, Johnson, report!... _Johnson!_"

Silence.

Grimly, Jason watched the vertical bar of different brightness edge back to the Fane's East wall and disappear into the even dazzle of the marble. He had a feeling it wasn't any use calling Johnson again. Ever.

"Chief, what's up? What do we do?"

"Huh? Oh ... You, Holland, get over to the East Entry as fast as your legs'll stretch."

"There in three minutes flat!"

"You, too, McGillis."

"On my way!"

"Adams, you stick at that West Entry. If anything gets past you, I'll--"

"Don't worry, Chief. I've got Johnson to even up for."

Not watching how he ran, Jason hurled himself toward the East Entry; his eyes following, in the opposite direction, a dullness moving in the blaze inside the Fane. A smoothly moving, white on white, unfaced ghost of whiteness within, a part of, the blazing radionic light. Just as he rounded the East end of the Fane, he glimpsed the vertical bar of whiteness again--the edge of the marble slab that was the entry door, reflecting the blazing light at a different angle. Behind it, McGillis's tightly grinning face. Under McGillis's face, the stab of blue-white light reflected a glancing ray from the old-fashioned solid-missile service pistol that Jason had insisted all four men arm themselves with for this a.s.signment.

Over the sound of his own labored breathing as he plunged through the East Entry, Jason heard panting behind him. Holland. Holland bettering his promised three minutes--and with a forbidden disarmer in his hand.

Guiltily, Jason felt the weight of the disarmer he had himself secreted under his armpit.

Then there wasn't time for thinking or feeling, only for running down the dazzling half-mile inside the Fane to the Tiara. Up ahead, the different-white shape was motionless in front of it. Oddly, a dark, vertical line appeared from the top to what would be the waist of the shape. And for the instant it took the Tiara to vanish inside, Jason saw clearly in the radiant light the profile of Lonnie's unmistakable face.

Saw Lonnie's eyes swivel in the direction of the thundering echoes of their footfalls in the silence of the Fane. Saw Lonnie turn toward them, the dark line disappearing from waist to top as if it had never been.

Once more the different-whiteness moved. Toward them. Edging for the back wall to skirt around them; one limb-shape fumbling in the palm of the other.

"No you don't!" McGillis, ahead of Jason, yelled, his howl drowned in the smacking crack of his pistol.

There seemed to be a waver in the different-whiteness. A small black dot appeared against it; hung briefly, apparently unsupported, in the air; then the undistorted bullet dropped inertly to the floor.

"You _still_ won't!" McGillis hurled himself, shoulders low and legs driving, at the shape. Two feet from it, he rebounded sharply, trod on the rolling bullet, went down, his head splatting dully against the marble floor.

Holland grunted. Crouched to leap. Thrust his disarmer high, ready to snap into line.

"Hold it!" Jason commanded. Silently, eyelids barely separated to endure the dazzle, he stared at the different-whiteness that confronted him. "I made it this time, Lonnie," he called. "Caught up with you-- No!" His arm flung out, startling him with the feel of his disarmer now oddly in his hand.

"Don't move!"

The white-within-white's limb-shapes moved up, the hand-ends one over the other. Through the minute s.p.a.ces the overlapping fingers left, glimpses of a thin dark line appeared. The hood was open a trifle at mouth level, and from the opening Lonnie's voice emerged, sifting through the protecting screen of gloves. "You can't see me! You _can't_!"

"No? Take one step sideways. Just _one_! Stop!"

The different-whiteness had moved, and Holland had moved with it; crouching now, alertly motionless, in his new position. Jason changed the angle of his own facing. "Now do you think we can't see you?"

"But ... but how!"

"Your albedo is showing," Jason chuckled harshly. "You never would take the trouble to learn the _how_ of anything, Lonnie. Sure, your d.a.m.ned disguise is the same color as the marble. Maybe even exactly the same.

But the material is different, and the surface texture; it doesn't have the same degree or quality of reflectivity to incident light that marble does!

"Eighty years ago, even the commercial photographers knew about albedo--one of 'em made a picture of a cat, white on white. I told you about the reflectivity in your stereo cube. But you wouldn't listen, Lonnie, would you?" Jason let out a bursting peal of laughter. "_So you tripped over your own albedo!_"