“It wouldna happen to be a straight line, would it?”

“Looks like it is. Man-made?”

“Aye.” Iseabail smiled. “Dinna worry, cap’n, ye’ll be out a jiffy. What d’ye weigh?”

“About a hundred and seventy pounds.” Beyond his mouth, Cannon moved as little as possible. “Why?”

“Ye’ll see in a moment. Wha’s that in stone?” For a few seconds, Iseabail mouthed numbers. “If somethin’ happens tae make ye have ta move, give a shout an’ dinna fall forward, aye?” Cannon nodded. “The rest of ye, grab rocks from yon other pile an’ pass them here.”

Burr and di Giacomo lined up, and after a moment, Masaracchia caught on and finished the chain. Isea hefted each piece of rubble carefully before setting it in a growing pile next to Cannon. Eventually, she held up a hand at Burr, and said, “Gingerly, now, cap’n.”

Cannon shifted his weight backward, straining his ears for any slightest noise of the plate shifting. None came, and he stepped fully off of it. “Remind me to get you something nice.”

“We’ll call it even if ye can get me inta Jimmy Ellis’s club.”

“In San Francisco?” Cannon raised his eyebrows. “Maybe. We’ll work it out later. For now, we have a job to do.”

Iseabail shared a put-upon look with Burr. “Well, at least ye dinna pay me badly.”

They pressed onward, Cannon leading at a more measured pace. In fifty yards, they came to a door, decorated with pictograms, in the center of a brick wall across the tunnel.

“What do they say?” said Burr.

“These are more decorative than the others.” Cannon frowned, looking from row to row. “I don’t know this style. There’s Amen-ta again.” Here, the glyph was brilliantly colored: an orange half-circle, at the same time somehow both dusky and luminescent, over the midnight blue lines of the river. “There’s Osiris.” The glyph bore a strong resemblance to the statue in the gallery, though here Osiris still had his pale green coloring, and it was obvious that his legs were wrapped in linen. Cannon knelt to finish the last few lines. “That’s all I can make out. How do we get it open?”