No web tricks here; the entire puzzle is on this page. You've solved it when you know where the treasure is hidden.
Thanks to Denis, Marc, Shmike, and Laurel Ann for test-solving.
This puzzle is, in part, an homage to Christopher Manson's puzzle-book Maze. No, knowing that won't help you solve it. (Addendum: here is a nicer Web adaptation of the book. Possibly unauthorized, but nice.)
"A fabulous treasure?" said one. "In this place? Looks like the owner was selling the furniture before the end. Even the carpet has been torn up."
"Appearances can be deceiving," I said soothingly.
"What do you know about it? When was the last time you were in here?"
"Not for years," I lied.
"Well, someone has been," another one said, peering at the floor. "Footprints in the dust."
Drat. I try to take care of those. The group bolted off like hounds, through the wrong door entirely, into...
Most of them were, anyhow. "The hinges on this stove are clean!" someone noticed. Well, cleaner. They attacked it vigorously, first by hand and then with the crowbar they'd found earlier. After a great deal of effort, they pried the door loose... and discovered what might have been a roast, decades ago. Nothing more.
Disgusted, they chose a door -- nobody wanted to re-cross the bottomless pit. "Locked... but from this side," reported the leader, and glanced through. "No, we've been that way." He opened the other one, and we continued to...
No one thought to ask where the main bathroom was. No one ever did. It didn't matter.
"Now where?" one asked.
Another peered through a keyhole. "Not this way -- it just leads back to where we started."
"Of course it does!" someone groaned. "We've been turning to the same side ever since we arrived."
Not a reliable guide, in this place, but she happened to be correct. At any rate, everyone agreed to try the other way for once. They opened the door and discovered...
One of the group did start picking out the monogram on the silver. "G... Y... O... B? Or maybe the last two are zero-six, they're smaller..."
"This is where that dumbwaiter goes to, anyway," I said, in an attempt to distract the rest. They were too worn out to care, which was fine by me. They chose a door, which took them to...
"I have to keep them smoldering, or the pipes would freeze!" I shouted apologetically. That wasn't the reason at all, but none of them were clever enough to realize it.
They tried digging into the coal bins, but soon realized there was far too much of the stuff. Besides, searching through coal in a nearly-black room is even more useless than the rest of their quest. Eventually they tired of the headache-inducing clangor, and headed on to...
"I thought you didn't live here," someone asked suspiciously.
"Ah..." I began, but was fortuitously interrupted by a horrible noise. They all piled out in that direction. I reflected on what a surprise they'd have had if they'd tried reading any of the books, and followed them to...
As the group debated which way to turn next, a loud hammering sound made them all jump. Clearly we were once again in the vicinity of the boilers. Eliminating the door that led that way, and the one we'd entered by, left only one choice. A flight of narrow, creaking stairs climbed to...
"Didn't we search the rafters already?" one of them asked. But the rest decided that that must have been on the other side of the house. (It hadn't been.) They began searching once again, albeit with less vigor. The quest takes its toll.
Somebody found a crowbar, which wasn't treasure but seemed likely to be useful. Aside from that, the room was a loss.
One of them gave up on dusty boxes, and frowned at the two unexplored exits. "Have you noticed that every room we've been in has had the same number of doors?" he asked.
"You saw two in the pantry," I pointed out innocently. "And the antechamber had four."
He looked disappointed, and turned back to the doors -- the unlocked one, at any rate. "Folks? I think I see something down this hallway." That got everyone's attention, and we left for...
"Well, the original term was--" I began.
"The hell with the original term," said one of the heavier members of the group, collapsing onto a sofa. "I thought those stairs would never end." Everyone agreed it was long past time for a rest.
There's always one, though, and in this case it was the one peering suspiciously at the piano. "Help me get the top open," he said to general groans. The thing was locked tight, though. He couldn't get a thing out of it, unless you count muffled clunking noises from the keyboard. And the group had, with their typical resourcefulness, left the crowbar behind.
The inquisitive sod wanted to go back for it, but he was unanimously overruled. Everyone tramped wearily onwards to...
"You couldn't have warned us?" they wailed, balancing on the few boards that protruded near the door. I shrugged helplessly. This was their quest. I tried not to crowd them any farther forward than I had to.
A plank lay across the abyss, and two doors were visible on the far wall. "We could go back to the bedroom," someone asked hopefully, but everyone else decided to push on. Perhaps not the best idea, but they made it across.
One of them, counting heads, asked "Aren't we missing someone?" I shrugged again. They couldn't remember how many they'd started with, which ought to have been a warning signal. I just suggested they move onwards. They did; our next stop was...
The first exit they tried was locked. "Do you still have that key?" someone asked, but it turned out to have been lost. Or perhaps its holder had been. But I didn't point that possibility out. The other door took us to...
"Well," someone said after a while.
The hanging crystal is impressive, I admit. The skylights are considerably cleaner than most of the house's windows -- this room is my one touch of vanity -- so the chandeliers glint color onto every surface.
By then their eyes had adjusted; it was far brighter here than in the room they'd emerged from. And far brighter than either of the rooms they could go next, but I didn't tell them that.
The group wasted a lot of time trying to figure out if any of the glass was secretly diamond, but finally headed to...
But then someone realized that the painted vault-door frame concealed the cracks of a panel that was quite real. They pried at it, but couldn't get it open. (No surprise; the latch was on the pantry side.)
After a lot of frustrated pounding, they gave it up as a bad job. "Maybe it's a fake false secret door," one of them muttered, as they headed for the door midway down the hall. It opened easily, and led to...
They all agreed that an attic was a likely place for hiding treasure, and began tearing the room apart. I let them. They'd seen barely any of the house yet, and they might as well expend their energies where there was nothing to find. Not that I expected too much. They might not be total idiots, but they'd missed that secret door earlier, hadn't they?
As expected, they turned up nothing but old filth from the bats that sometimes nested. When they gave up, they chose an exit which led to...
They didn't care for my help. "What is this?" one asked. "A pile of broken sticks, leave it," said another. "No, I think they were arrows," said the first, but nobody was listening.
They gave the place a cursory going-over, but they were clearly wearying. "What is this, the eleventh room we've been in?"
"You've passed the halfway mark," I said cheerfully. "Which means it's the tenth from the end. You ought to start counting backwards, see? The numbers will be smaller." They didn't care for that, either.
They were even less pleased to discover that both of the doors onward were locked. "What about that key you found?" someone suggested. It turned out to fit one of the locks, fortunately. The door opened on a broad stairwell; everyone moved through to...
The group was getting frustrated by now; and the thought of a living creature, perhaps hunting them, had them on edge. They broke into furious argument about which way to go next. I didn't tell them that they were closer to their destination than they'd been since the beginning. It wouldn't have helped, anyhow -- they settled on the wrong exit. I followed them into...
Eventually they tired of the alchemical stench and chose a door. Fortunately, the bolt was on this side, and we moved on to...
They searched the shelves diligently. "A key!" shouted one finally.
"Excellent!" I said. My enthusiasm was sincere; not many groups think to look inside the sausage grinder. But then they decided they'd found all there was to find. I hid a smile as they opened the only visible door, and trooped out to...
One of the group said she smelled something. "Not chemicals, it's... animal."
"Must be the bats," someone said dismissively.
"No, they were long gone. This is... alive. And I'm not sure it's coming from above..." I held my tongue. Some things it was better none of us disturbed.
There were other doors off the landing, as it happened. We picked one at random, which led to...
Everyone slowly spread out across the room, unwilling to disturb the stillness. Light flickered behind the glass insets in the walls, spelling out constellations and comets, asteroids and nebulae. It gleamed on the brass planets and moons which hung motionless on their tracks. But it utterly failed to illuminate the glass sunburst in the center of the chamber. That might once have been filled with fire; now it was black and opaque, impenetrable.
"You've seen all there is to see," I said. "If you haven't found the treasure's hiding place by now, it's time to go." I indicated which door led back to the Antechamber.
They huddled, consulting their notes. I left them to it. They'd follow soon enough, to their starting point and then from this place. Despite all their mistakes, they had followed the correct path. What they did not understand -- what no one ever understood -- was that the significance of each room was not in what they saw, but in the path they had not taken.