Socotra is an island in the Arabian Sea, 350 kilometres off the coast of Yemen, isolated for so long that a third of its plants grow nowhere else on Earth, chief among them a tree shaped like an umbrella turned inside out that bleeds red resin when its bark is cut. The tree is the dragon's blood tree, and on the Diksam plateau it grows in loose forests on open red rock, some right at the rim of the canyons that cut through the plateau with nothing but air behind them; its upturned crown is a survival tool that combs moisture out of the mountain mist and funnels it down the trunk to the roots. A local scores the pale bark and catches the thick crimson resin that seeps out drop by drop, the dragon's blood that gave the tree and the island its name, traded for two thousand years as a dye, a medicine and a varnish. The forests are thinning, with few young trees, and those standing are old.
The rest of the island is as strange. Bottle-trunked desert roses cling to the cliffs with fat grey trunks and pink flowers, peaking in March; cucumber trees stand on swollen stems; and in the granite Haghier highlands at the island's heart clouds snag on jagged peaks and cold streams gather in rock pools. At Arher, on the northeast coast, white sand piles hundreds of metres up against a wall of dark cliffs and a cold freshwater stream runs down through the dunes into the sea; at Homhil a natural rock pool sits at the lip of a cliff like an infinity pool above the coast; and Hoq Cave runs three kilometres into the mountain past forests of stalagmites and pools of still water. The beaches are white and empty, and the sea is full of fish. Socotra is reached by a weekly flight, its people speak their own language, and the war on the mainland has kept it both cut off and untouched. Socotra is an island that evolved on its own, and the trees on it bleed.