Onyx climbed out from the rock seam above the panel frame and moved along the ceiling of the alcove with liquid ease, his black body nearly invisible against the dark granite above the candlelight's reach.
He stopped directly above the dry timber panel that Toby had been pressing his palm against, and tapped his tail against the ceiling surface twice.
Then he ran sideways along the ceiling seam to a spot two feet left of the panel frame and tapped again.
Toby watched this sequence with absolute attention.
He had grown up reading his father's technical survey maps, and he understood how to extract directional meaning from spatial pattern.
The gecko was not moving randomly.
He was indicating something specific about the geometry of the space behind that wall panel.
"Pip," Toby said softly.
"Sit."
Pip sat, watching Toby with intense, patient eyes.
Toby reached down to his tool belt and unclipped his iron hand-pick: a short, heavy tool with a curved iron head forged for working in confined spaces.
He examined the frame of the dry wall panel carefully in the candlelight.
The panel was constructed from Victorian red cedar, installed in 1895 based on the site schematics he had studied.
After fifty years of isolation, the cedar had dried to a state of significant brittleness, particularly along the lower frame rails where groundwater had caused repeated cycles of wet and dry.
He placed the curved iron head of the pick against the lower left corner of the frame rail, angled at forty-five degrees to the joint between the cedar frame and the surrounding granite mortar.
He gave a single firm push.
The cedar frame moved.
It did not break — it deflected inward, revealing a clear gap of almost one inch between the frame rail and the granite face behind it.
From that gap, a strong, steady current of cool, clean outside air poured over Toby's face, carrying the unmistakable scent of pine resin, damp granite, and high-altitude oxygen.
Toby closed his eyes for exactly two seconds.
"It's open behind here," he said quietly.
"The Victorian drainage flue."
"It's right behind this panel and it's open."
He repositioned the pick, hooking the curved head behind the cedar frame rail and using the shaft as a lever arm, pressing his full body weight down against the handle.
The old cedar let out a series of sharp, progressive cracking sounds, each one releasing years of compression in the joint mortar.
The frame rail shattered along its full length and the wall panel folded inward.
Behind it was a rectangular opening sixty centimetres wide and ninety centimetres tall, cut through the granite face into a narrow brick-lined passage that ran away from the alcove in a gentle upward incline.
The brick was old Victorian red clay, precisely laid, its mortar still clean and intact after a century of isolation.
The air current flowing through the passage was strong, steady, and completely fresh.
Onyx dropped from the ceiling to the brick ledge of the opening in a single fluid movement.
He looked back at Toby with calm golden eyes, then turned and trotted fifteen feet into the brick corridor, stopped, and looked back again.
"After you, then," Toby said.
He tucked Pip under his left arm, secured his tool belt, picked up the candle stump in his right hand, and stepped through the opening into the Victorian drainage flue.
The cedar panel rail came apart in three sections under sustained leverage pressure from the iron pick.
Toby worked methodically, repositioning the pick head after each section fractured, maintaining a controlled removal rather than a frantic demolition.
He needed the surrounding mortar joints to stay intact.
A collapsed frame would block the opening.
The first rail section came away cleanly, exposing a twelve-centimetre gap between the panel and the granite face behind it.
The air current through the gap was now strong enough to gutter the candle flame sideways.
Toby repositioned the candle behind his body to shield it and continued with the second rail section.
Pip watched from a position three feet back, sitting very still in the water, his eyes fixed on the work with focused intensity.
He had stopped barking.
He had assessed that barking was not currently useful and had discontinued it.
The second rail section fractured along a natural grain line and fell inward with a hollow clatter against the brick surface of the flue.
The third section — the upper frame rail — was in better condition than the lower two, the wood less degraded by groundwater cycling.
Toby spent ninety seconds on it.
He worked the pick head along the entire length of the rail, loosening the mortar joint incrementally before applying final leverage.
When it went, it went completely: a full-length fracture along the grain that separated the rail cleanly from its mortar mounts and left the opening fully unobstructed.
The gap was sixty centimetres wide and ninety centimetres tall.
Behind it, visible in the candlelight, was the interior of a brick-lined passage running upward at a shallow angle, its walls constructed from hand-pressed Victorian red clay brick in a running bond pattern, its mortar white and clean and completely intact.
Onyx appeared in the opening before Toby had fully straightened up.
The black gecko glided over the brick ledge, moved ten paces up the corridor, and stopped.
He looked back.
His tail was still.
His golden eyes were absolutely clear.
"Lead on, then," Toby said.