Cranmere Pool! The most desolate spot on Dartmoor. Here rise seven rivers—born in the quaking morass, itself the result of the drainage of the giant tors which shut it in on every hand. A lonely spot encircled by the everlasting hills, without a road or cart-track—inaccessible, isolated. In summer visited by tourists who boast of having made the pilgrimage on the hardy little moorland ponies; in winter as solitary and forsaken as the Great Sahara itself. Half a mile from the pool is a low, grassy plateau from which the hills slope upwards, and half-way up is the remains of a ruined house—the walls of which are only a few feet high, and are level with the ground in many places. A strange place for a house until one notices the hummocks and depressions in the rock-strewn heather, and then one realises that once in far-off times this was a primitive tin mine. The silence is intense—the hillside, save for the heather, bare and lifeless. Suddenly a clump of heather stirs, and a man’s head appears thrust out of the hillside itself—followed by his body—as it emerges from a hole hidden by the heather. He raises a pair of Zeiss glasses and carefully sweeps the country—first the foot hills, then the more distant tors. Then having satisfied himself that he is the sole human being on that wild moorland, he throws himself into the heather—and fills and lights a pipe. Rupert’s waiting place had been well chosen. For anyone but a born moorman it would have been impossible. Dressed in a smart blue suit, his hair of decent length, and a decent moustache, it would have been difficult to recognise in him Convict 381! He lay on his back and nervously blew smoke rings into the blue vault above him. Presently he ceased smoking and sat up. A faint humming greeted his ears! He rose to his feet and faced the north; his glasses swept round the skyline east and west—then he took them down and gazed slowly round the visible horizon. Nothing in sight, and yet the hum increased. Now it stopped suddenly. He looked up, and there, right above him, was a monoplane, far up in the blue heavens, circling round and descending in great spiral swoops till he could see the figure of the pilot. With a strangled cry of joy he ran down the steep hillside to the grassy plain, and presently the monoplane swooped down and bounded along the rough turf. Rupert raced after it, and as gradually, almost imperceptibly, it slackened speed, he seized hold of it and used his weight to help bring it to a standstill, Crichton eventually jumping from his seat and doing the same. Then Jim took off his safety helmet and the two men faced one another. Rupert held out his hand. He tried to speak, but he could not trust himself. Jim Crichton understood; he, too, had a queer sensation of choking in his throat.