In the dense, grey-green scrub of the Tomakin headland, Jorge Luis Borges rested his hand on a furrowed banksia trunk. A few paces away, Charles Lutwidge Dodgson knelt in the sand with a small wooden ruler and a pocket notebook, carefully drawing a coordinate grid around the tracks of a scuttling hermit crab.

“We are caught in a recurring decimal, Mr. Borges,” Dodgson said, tapping his pencil against the notebook.

“Have you established that it is the same root?” Borges asked softly, his sightless eyes turned toward the rustle of unseen foliage.

Dodgson paused, his pencil hovering. He leaned closer to the bark, inspecting the grey lichen and the intricate scarring of the wood.

“It possesses four nodes,” Dodgson muttered, recording the millimeter count. “And a characteristic fissure resembling the letter Z.”

“Did the first root possess that fissure?”

Dodgson blinked, looking up from his grid. “I did not record the fissure.”

“Then we have found something you did not record,” Borges murmured, a faint, serene smile touching his lips.

Dodgson straightened his waistcoat, frowning down at the sand where the crab had just vanished into a clump of wiregrass.

“We need a rule for choosing the path,” Dodgson said, his voice rising with academic testiness.

“And for choosing the rule?”

Dodgson opened his notebook again. He stared at the blank margin, his pencil poised above the paper. The afternoon light fractured through the canopy into dozens of identical, uncertain clearings around their boots.

Dodgson closed the cover with a brisk snap and tucked it into his pocket.

“We could follow the crab,” Dodgson said.

Neither could find its tracks.