Alex nodded, and explained Amel’s view that some of the Crusaders, who had remained behind after the successful First Crusade, had become fascinated by the architecture and ideas of Islam, and the spirituality of the Sufis. The Christians had been initiated into much wisdom and some arcane knowledge from the Jewish and Muslim population in Jerusalem whom they hadn’t slaughtered, but in particular it was the beauties and ideas behind the Aksa Mosque, on the Haram el Sharif, that had left an indelible impression. This was the Temple Mount, from which Muhammad was said to have made his mystical ascent, the night journey into heaven. Contrasted with Constantine’s lumbering Church of the Holy Sepulchre, it seemed effortlessly beautiful and spiritual. The Sufis taught them that the pointed arch raises the energy and spirit heavenward, whereas the Roman arch redirected the forces to earth.

“And the Sufis honored Christ as one of the seven sages of Islam?”

Alex replenished the glasses. “As do all good Muslims. But Amel explained they were strongly committed to a pluralism—which also interested Dee and Bruno. The Sufis recognized that every religion contained reflections and descent from one universal truth. They were tolerant, highly educated, at ease with the Torah as well as Christian teaching. A lot of coded architecture in great Gothic buildings—like Chartres, and St. Denis in Paris—might be traced to the mystical teachings of the Sufis, through the Templars. They held the number nine sacred; and there were nine Templar knights. No more were added for nine years.”

“I’ve read about the arches. Let me check my notes.” Grace dipped in her work folder and showed Alex some pages with her own line drawings. “The Druidic and Celtic associations are also linked with the number nine, the Triple Goddess. When the cathedral was rebuilt after a fire late in the twelfth century, new doors were added to make nine, and nine arches—the mukhamma Islamic arches you’re talking about. Hardly a coincidence.”

They studied the floor plan she’d reproduced, and Alex’s finger bounced as he came to the data that the paved stones of the labyrinth were each thirty-four centimeters in length. “A strange detail—though centimeters came in with Napoleon. But the number pattern suggests interfaith plurality,” he said. “It’s inspiring, don’t you think?”

Grace’s face betrayed deep thought. “Not for all people, Alex. It might shake the absolutes of their religion. But, where does this bring us in relation to Dr. Dee and his friends? And why did it matter to your mother?”

Alex took out his wallet and carefully unfolded a small sheet of paper. “I copied this last night from one of Will’s reference books. I recognized it straight away from our old family Bible, where someone had drawn it—which always caught my attention as a boy. Now I know it’s Dee’s emblem, called the ‘Monas’ or ‘one.’”