When The Firefly got into the Bay of Biscay the weather was worse than ever. Giles was pleased, as Calthorpe told him that there was the better chance of catching The Dark Horse before she reached her port of destination. Once on Spanish soil and Giles feared lest Morley should carry Anne off to the mountains. He was such a scoundrel, and so clever, that it might be possible he had confederates at Bilbao to help him to carry out any scheme he might suggest. Giles wished to catch him before he had time to formulate any new villainy. At all events, Morley would never think that they had tracked him so speedily, or had followed so rapidly. It was unlikely that he would use the yacht to the fullest extent of her steaming powers.

In the centre of the Bay The Firefly was caught by the full force of the storm. The wind and waves were terrific, but the gallant little boat proved herself trustworthy. Under a sullen sky, over a dismal grey sea she steamed, her decks streaming with water, and the ship herself rolling terribly.

Calthorpe did not slacken speed, and the boat responded splendidly to his handling. A sharp lookout was kept by all on board for the yacht, as Giles had offered a large reward for the first man who espied the boat. But the difficulty was that none of the crew knew the looks of The Dark Horse. However, they were to hail when they saw anything in the shape of a yacht, and there were one or two false alarms. At length, when The Firefly was approaching the Spanish coast, Dane, who was on deck with a glass, gave the alarm. It was a misty, grey day, with absence of sun and wind. The ocean was heaving like masses of liquid pitch with an oily look, and the yacht cut sheer through the terrific waves that threatened to overwhelm her. Suddenly a wind rose, there was a blink of sunshine, and about a mile away a bark was seen rolling in the trough of the sea. "There she is!" roared Dane, and every one came on deck.

"Are you sure?" cried Giles, taking the glass.

"Perfectly sure," replied Dane, who was dangerously excited. "Captain, let me handle the wheel as a reward."

Calthorpe gave his assent, as he knew what a good steersman Dane was. He then took his post beside Giles and Steel, who were admitted on to the bridge, and thence directed the ship. Then The Firefly made a bee-line for the distant ship.

Steel and Giles had less sense than they should have had; and Dane in his joy at the sight of his prey quite forgot that with a good glass Morley could recognize them all three. It was The Red Cross, alias The Dark Horse, that was steaming leisurely southward, and doing her best to battle with the strong seas that hammered her newly painted sides. Thus Morley, who had never expected such promptitude, became aware that his foes were at his heels. He saw the detective and Giles on the bridge. But Dane he did not see, being in too much of a hurry after his first glimpse of the danger to take further interest in those on board The Firefly. The result of Morley's decision was that those on the pursuing yacht saw clouds of smoke pouring out of the funnel, and knew that the furnaces were being crammed to suffocation. There was a shout of joy from The Firefly's crew, for now the fun was beginning.

"We'll see if she'll beat my boat," said Calthorpe on the bridge.

It was very stormy, and black clouds were racing across a pallid sky. A furious wind had blown the mists into shreds of vapor, and was ripping white spume from the tops of the rearing waves. The vessel in flight soared like a swallow, and slid down into mile-long valleys; but The Firefly, having more powerful engines, tore straight through the walls of water that threatened to block her way. She trembled with the vibration of her screws, and in the stormy heaving of the water there was great danger lest her propeller fans should snap. However, the engineer stood with his hand on the throttle-valve, and stopped the spinning of the screws when they emerged.

Much the same tactics were being pursued on board The Dark Horse, save that in addition the safety-valve was tied down. The engines worked at furious speed, and the boat leaped like a hunted stag. But the hound on its heels came closer and closer, and those on The Dark Horse could hear the roar of the delighted Firefly crew. Morley ground his teeth, and fed his furnaces again. Anne came on deck.