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Jump to ExcerptsLabyrinths in Prodigal Logic

Many of Europe's old cathedrals contain a labyrinth in the center of their nave, placed their by their master architects for unknown reasons. Today, labyrinths can be found in churches, gardens and other peaceful settings; they are gaining in popularity as a metaphor for pilgrimage or a spiritual journey.

The imagery of a labyrinth -- its sense of mystery and its metaphor of a meandering but purposeful path -- make it a compelling theme to include in a mystery novel.


In Prodigal Logic, understanding the significance of the labyrinth in the University Cathedral is essential to unlocking the puzzle of the plot. Ray Gabriel, the quintessential rational thinker, is being slowly educated by Miriam Towson to the cathedral's beauty. The two are sitting in a second-tier balcony watching a funeral when Ray first notices the labyrinth. (Click here to jump to the Labyrinth links and webrings at the bottom of this page.)


I trained the binoculars on the north transept, looking for the Saint Peter's statue, but the angle made it impossible to see the small chapel. I panned out to the middle of the nave. My view was drawn to a circular design of light and dark marble tiles, about forty feet in diameter. I remembered crossing these tiles when Miriam had first given me a tour of the cathedral and wondering if they had been placed randomly. From this distance, I could see that the dark and light stones did indeed form some kind of pattern.

"Miriam, check this out," I said, handing her the glasses and directing her to the spot. "What's that marble pattern in the floor?"

"That's a unicursal labyrinth. They're common in medieval cathedrals."

Retrieving the glasses, I re-focused them. The lighter tiles of the labyrinth etched an almost symmetrical path through the circle. There was only a single point where this pathway intersected the inner circle, and only a single entry point into the labyrinth, at the point farthest away from us. Starting from that entrance, I mentally traversed the path. There were no intersection points, no wrong turns or dead ends. The path continuously turned back on itself, like a coiled snake. At journey's end, my imaginary feet were standing firmly in the circle at the center of the labyrinth. This inner circle was about six feet in diameter, with six smaller half-ovals attached to its circumference.

Unicursal, Miriam had said. I sounded it out. "Unicursal. One Course." Miriam nodded. "And the symbolic significance?"

"No one really knows. The labyrinth was popular with pilgrims to the cathedral. They would walk it from the entrance to the inside and then back out again. It taught them that if they persevered on the path of good, no matter what the difficulties, they would inevitably end up with God in the next life. I suppose the center circle represents heaven." She shifted in her seat. "Why are you so interested in the labyrinth, Ray? We should pay attention to the funeral."

Something about the labyrinth fascinated me. It was similar to the gargoyles, but in reverse. They jutted from the building at such a height that their design could hardly be appreciated. The labyrinth was large but at ground level it could easily go unnoticed. I entered a description of the labyrinth into Sherlock's knowledge base, along with Miriam's explanation of its historical significance.

Sherlock-in-a-Box is a smart computer system being developed by Ray to solve mysteries. But besides stretching his mental muscles, he is undergoing his own spiritual journey. On this other level, the author deftly weaves in the metaphor of the labyrinth as a journey to the center of your deepest self and back out into the world.

Later in the funeral scene, Ray enters information on the labyrinth into Sherlock-in-a-Box to see if the computer has come up with any new leads.

On the screen, Sherlock Holmes continued to puff on his pipe. Behind the detective's unruffled exterior, I knew Sherlock was jumping in and out of his thumbrules, backward chaining until he came to a dead end, meaning he had insufficient data. And insufficient data meant he had to ask a question.

"Any second now," I said. Finally the graphic of Sherlock Holmes disappeared, replaced by a question. But it wasn't the one I expected. It read, What is distance from west portal to labyrinth?

I looked at Miriam in surprise. "I entered some facts about the labyrinth while we've been up here. Sherlock must have connected it with our mystery."

Miriam seemed to tremble and looked unsteady. The funeral was taking its toll.

"Maybe we should leave," I said. "We can do this later. I'll measure the distance from the doors to the labyrinth after the funeral is over."

Miriam hugged her chest and took a deep breath, as though willing herself to be calm. "No need to measure it," she said. "It's one hundred twenty five feet."

"I'm impressed. How in the world do you know that?"

"'All things whatsoever observe a mutual order and this is the form that makes the universe like unto God.'"

"Meaning?"

"It's a quote from Dante. Medieval cathedrals were constructed using geometrical formulas, simple ratios whose relationships were intended to mirror the harmony of heaven. Everything's in a one-to-one or one-to-two ratio."

"I remember feeding in some articles about 'right measure' to Sherlock. Is that what you're talking about?"

"Yes. Take the nave," she said. "It's twice the width of the side aisles. All the wall pillars are equal to the length of the intersection of the nave and the transept. The distance between the pillars of each bay of the nave is in direct proportion to the height of the walls. Everything is related harmonically. If you know the ratios and the starting number, you can calculate the distance between any two points in the cathedral."

I was genuinely impressed. As well as having an aesthetic feel for beauty, Miriam was obviously mathematically inclined. I realized that the two were in balance in this building. But I wondered why Sherlock would care about the distance to the labyrinth. I dutifully typed in the number that Miriam had given me.

Sherlock digested the response. "Look what he's asking now," I said, angling the screen toward her. What is shape of labyrinth?

I typed in "Round."

Does labyrinth have half-circles on circumference?

Half-circles on the circumference. I recognized this phrase. I had entered it into Sherlock to describe the sketch we had found.

I hefted the binoculars again to examine the labyrinth. Its inner circle had six smaller half-circles connected to its circumference, reminiscent of the petals of a flower. The flower illuminates the time and the place. A chill quivered through me. I entered "Yes." The program responded with, What number half-circles has labyrinth?

Six. The same number as was on the sketch. I temporarily suspended Sherlock-in-a-Box, and brought up the picture of the Numbers of the Rose sketch on the computer.

There was indeed a resemblance between the circles on the sketch and on the labyrinth. "It looks to me," I said to Miriam, "that we were wrong to think that the figure on the sketch was a rose. It's actually the center of the labyrinth."

I checked to see if she had made the same connection. Her face had gone pale and she looked as though she were going to faint. I quickly set the computer down. "Miriam, are you okay?" I touched her shoulder. "Do you want to leave?"

She pushed my hand away. Slowly, methodically, she began to tap a closed fist against her chest. I was afraid she was having trouble breathing. Then I understood the gesture. She was praying.

"Give Sherlock his answer," she said.

"Are you sure, Miriam? Maybe we should..."

"Do it, Ray."

I typed in the answer. "Six."

Does rose window have vertical shaft connected to circle?

I looked out to the distance of the western entrance to the stained glass window. I typed in "No."

Does labyrinth have vertical shaft connected to circle?

I looked through the field glasses at the labyrinth. "I don't see any vertical shaft coming from the inner circle."

"That's because of our perspective," Miriam said softly. She took the binoculars and held them to her eyes. "If you follow the path of the labyrinth from the opposite end, it joins the circle just like it shows in the picture." She set the glasses down and looked at me. "From ground level, no one would connect the pattern in the labyrinth to the pattern in the sketch because of the perspective. And you didn't recognize it from here because you were looking at it upside down."

The use of the word "you" instead of "we" wasn't lost on me. Miriam had already deciphered the sketch, probably when I had shared Jon Matthias' comparison of the boxes to walking a winding path. "It has to be looked at from the other direction, from a height," she continued.

"You mean it has to be looked at from the rose window?"

Miriam brought a handkerchief to her puffed eyes. I was beginning to realize that there was more to her grief than the death of an old friend.