It was an hour after sunset, and a rich red glow still lingered in the western horizon, tinging the waters of the Thames as they swirled past the water-gate of Surrey House with gleams of scarlet and gold.

A young man stood on the brink of the river idly watching the ebb and flow of the tide.

For some time he had been strolling to and fro on the velvety lawn of my Lord of Surrey's house at Chelsea, as if awaiting a companion.

He was richly dressed, and the fading light glistened on many a jewel which bedecked his Court costume. It lit up the diamond cross of S. Iago of Toledo which he wore upon his breast, and gleamed on the diamonds which decked the pommel of the dress-sword which hung at his side.

Queen Mary was holding a Court revel this night at Whitehall in honour of her royal consort, King Philip, who had that day arrived in London from Spain, to the great joy of the Queen, and Don Diego d'Olivares was apparelled for the fête.

Don Diego was a typical Hidalgo of purest Castilian blood. His well-formed features, swarthy complexion, dark lustrous eyes, and glossy black locks proclaimed the fact.

"My father comes not," he murmured to himself. "If he delay much longer, I shall leave him to follow me to Court in Lord Surrey's company."

The light was fading off the river, the stars were becoming bright and lustrous, and the young courtier was growing impatient.

Few boats were on the river; now and then a galley or a wherry would dart by, and he noticed that the boatmen were lighting their torches.

He bethought him of the beautiful gardens at Whitehall, already gleaming beneath the light of hundreds of cressets. And his thoughts wandered to those whom he expected to meet there: the treasurer of Gray's Inn and his fair niece, Miss Susan Jefferay, the "heavenly twins," as he facetiously termed her two brothers William and Ralph, and many others.

For Don Diego was a legal student also—perfecting himself in the knowledge of English law at the Temple, by command of his renowned step-father, the Spanish Ambassador at the Court of Queen Mary.

He had met the twins at a masque at Gray's Inn, and a strong friendship had sprung up between the young men.

Thus he mused as he watched the passing boats on the silent waterway.

But Don Diego had not observed a dark wherry in which three men were seated, passing slowly up-stream.

He had not marked when the two oarsmen therein had thrust their boat under the shadow of the bank fifty feet higher up, nor did he see them land stealthily and creep silently into his rear as he sat on a bench on the top of the terrace.

Suddenly, and ere he could utter a cry for help, a shawl was thrown over his head, a gag was thrust into his mouth, a cord bound his arms to his side. Then he found himself lifted aloft by sturdy arms, and, despite his furious efforts, he was thrown violently into the boat, which at once pushed into the stream.

One of the oarsmen propelled the boat rapidly in the direction of London Bridge; his companions proceeded to further secure their captive with strong ropes, binding both hands and feet.

"That was a good haul, Bill," said one of the ruffians; "he is a fine bird, and will make good picking!"

"Stop your gab, you fool, till we get aboard the hulk, there are too many boats about," muttered his companion savagely.

The boat sped rapidly past Whitehall, where the lights were gleaming, and whence sounds of sweet music arose. They reached the ears of the poor prisoner as he lay at the mercy of his captors in the bottom of the boat, and they filled his heart with bitterness.

Should he ever hear those sounds again—would his eyes ever look again upon the fair scenes of earth?

Such were the thoughts that filled Don Diego's soul; he knew that he had fallen into the hands of merciless Thames pirates.

The boat was now rapidly nearing London Bridge, and the oarsmen prepared to shoot one of its narrow arches. The unfortunate captive had struggled desperately to loose the cords which bound his hands and feet; alas! all his efforts were in vain—he had been too securely bound by practised hands.

Yet he found it possible, by rubbing his head against the side of the boat, to disengage the gag which had almost suffocated him.

Then, collecting all his strength, he shrieked forth piercing cries for "help" until his captors had sprung upon him and had replaced the gag.

But his cries were not unheard, though he knew it not!

In the afternoon of that day William and Ralph Jefferay had gone down-stream to Greenwich Park, and had strolled awhile beneath the majestic elms and oaks which begirt the royal palace.

As evening fell they betook themselves to their light boat, and, being dexterous oarsmen, they made rapid progress against the swift-flowing tide, now on the ebb.

They had no time to spare, for both the young men had accepted invitations to the Queen's Revel at Whitehall, and they must needs go first to Gray's Inn.

They passed London Bridge beneath its widest arch, the central one, and were now opposite St. Paul's Wharf.

At this moment a piercing cry for help rent the air, and the twins instantly rested upon their oars, and listened eagerly for a repetition of the cry. Alas! there was none; the silence of night was again upon the river.

"Oh, Ralph!" said William, "that was a genuine cry for aid; it came from some poor creature in deadly peril. Oh! what can we do?"

"We will respond to it, by the help of God," replied Ralph; "it came, surely, from that dark wherry which I see yonder preparing to shoot the bridge."

"I thought so also," said William, "and methought I recognized the voice of him who called for help; it rang into my very soul, and, if I err not, it was the voice of our friend Diego!"

"To the rescue! to the rescue!" cried Ralph in reply, and in an instant they had turned their boat down-stream and were following the suspicious wherry.

Their light boat soon brought the heavier wherry into full view. They could see that there were three men on board of her; two were rowing, the third held the tiller.

"What are our plans, William?" said Ralph; "do you take the lead, and I will second you promptly."

"Agreed," replied his brother. "I propose, then, that we follow that wherry whithersoever it goes. If those men have a captive on board, they will soon seek to lodge him in durance—that will be our moment of attack.

"For the present we keep within reach of them, but sufficiently far off to disarm their suspicions.

"Leave the boat to me, I will row, and do you keep a vigilant eye on their movements. Loosen your poignard in its sheath—I will do the same—for this matter will not be decided without bloodshed, and may God defend the right!"

"Amen," said Ralph solemnly, yet with a distinct sound of joyous exultation in his voice.

No fear, no misgiving, found place in their brave young souls!

On the contrary, they rejoiced in the thought and belief that this was a call from Heaven, that they were God's ministers in carrying out a work of mercy and justice! A minute later both boats shot beneath London Bridge at a furious pace, the temporarily imprisoned tide hurling them on its strong bosom down-stream.

"They are making for the Surrey side," said Ralph; "it strikes me that they are going aboard one of those wretched hulks which line the shore; if so, what then?"

"I think you are right," replied his brother; "they would not dare to land their victim on shore, where they would at once encounter the watchmen. If these men are Thames pirates, as I strongly suspect, then these dark black hulks are their fitting and foul nests.

"Now, brother, take good heed, I beseech you—this is my plan. Presently the wherry will run alongside a hulk, and one man will leave the boat, mount the hulk, and proceed to make ready to disembark the captive. This is our moment to attack! We run in swiftly between the wherry and the hulk—so detaching them. Then we leap into the wherry, and our poignards must do the rest. It matters not what becomes of our little boat, a rescued life is worth a hundred such things."

"Right," said Ralph, "I understand; now put a good way on the boat, for, if I mistake not, they are running alongside a hulk."

Ralph was correct in his forecast; a moment later the wherry was alongside of a dark object, upon which one of the oarsmen sprung lightly with a rope in his hand. Then, with a loud crash, the light boat ran swiftly in between the two; and, above all, rang the fierce shouts and curses of the pirates.

But as they rose in their wherry the twins leapt into it—giving it a strong impulse into the stream.

There was no light on the hulk until the one man left upon it had lit a torch by whose lurid flame he sought to discover what had happened to his comrades.

So the fierce fight began in darkness, save for the gleam of the twinkling stars.

From their first onset the brothers perceived that their suspicions had been correct, for a bound man lay in the bottom of the boat, motionless and silent.

The surprise to the pirates had been complete, yet they had time to draw their long knives, with which they struck desperately at their foes.

It was a deadly struggle—there was no thought of asking or giving quarter; it was a matter of death or victory! Fierce blows were exchanged and parried; then the combatants closed, and the wherry swayed to and fro with a violence that threatened to submerge its occupants beneath the dark waters of the river.

The first gleam of light from the torch on the hulk fell upon a scene of fiercest strife—upon men in deadly grip, equally expert with their weapons, equally matched in strength and courage.

All were wounded, and the fast flowing blood rendered the planks of the wherry a slippery foot-hold.

Suddenly William's foe lost his balance; in an instant he was hurled overboard, and sank beneath the waters. His comrade perceived this, and with a howl of rage he also flung himself into the stream—for he was desperately wounded, and, as William approached to his brothers aid, he knew that the end had come.

Then the brothers turned eagerly to each other, and the question arose from both alike—

"Brother, are you hurt?"

"Not much, I think," said William.

"Mere flesh wounds," said Ralph almost gaily.

Then the twins joined hands and kissed each other on the cheek.

"Let us kneel down and thank God!" whispered William.

So they knelt side by side like two Christian warriors!

Presently they rose, and now they turned their attention to the captive in the boat, who had ofttime been trampled under foot in the strife.

"He is gagged," said William; "I will unloose him."

For a few moments the rescued man was well-nigh unconscious through the pain and suffering he had undergone. Then the well-known voices of his friends the twins fell upon his ears like heavenly music, and he spake.

"Brothers," he said, "will you cut my bonds?"

"By Heaven!" cried William, "it is Diego. Oh, thank God!"

Then they cut his bonds, and the young Spaniard rose with great difficulty, so benumbed were his limbs.

"Oh! my brothers," he cried, seizing their hands, "you have risked your lives to save mine, and Heaven has blessed your noble efforts; henceforth we are more than friends—we are brothers in heart and soul while life lasts.

"Ah! I see that you are both wounded—you have shed your blood to save my life! How shall I thank you enough? Oh, may Heaven reward you! But come, let me examine your wounds; it is my turn now to turn rescuer."

Ere Diego could carry out his intention, William sank suddenly into the bottom of the boat; he had fainted from loss of blood.

A moment later Ralph lay beside him from like cause.

"Oh, my brothers!" cried Diego in agonizing tones, "you will die before I can find succour for you; my poor life were not worth so great a sacrifice!"

His first thought was to seize the oars and strive to reach Greenwich—the lights of the town were now plainly visible.

Or he would strive to stanch their gaping wounds, and leave the boat to be borne forward by the rapid tide. While he thus hesitated, a sudden light appeared on the surface of the river, and his ears caught the welcome sound of the oars of a practised crew.

It was a Queen's guardship, and as it rapidly neared the wherry Don Diego uttered a loud shout for help. His appeal found instant and joyous response, for on board that ship were his father and Lord Surrey.

A Chelsea boatman had witnessed his capture, and had instantly given the alarm.

Yet so long a time had it taken before the guardship at Whitehall wharf could be sent in pursuit of the pirates, that its aid would have been too late, but for the Heaven-sent interposition of the twins.

The guardship rapidly drew alongside the wherry, and in a few minutes the wounded men and Diego were taken on board.

With tender care William and Ralph were carried into the little cabin, and a ship's surgeon made immediate examination of their injuries.

To the joy of Diego, he reported that though both the brothers were sorely lacerated, yet no desperate injury had been inflicted—they had lost much blood, and were thereby rendered unconscious; a few days' careful nursing was all that was required.

The guardship soon reached Whitehall, and there, litters having been procured for the brothers, they were forthwith conveyed to their lodgings in Gray's Inn.

Nor did Don Diego leave them till he had seen them safely consigned to the care of Miss Susan Jefferay, who had lately come to town from Chiddingly Place on a visit to her uncle, Sir John.