A FREEZING night in November, a cutting wind sweeping up from the Baltic, a sky so black with heavy clouds that not a star gleamed through, and the sentries on the walls of Stralsund shivered at their posts.

It was the only city in Pomerania still held for Karl; everything was ready for defense in case of an attack, and the eyes and ears of the sentinels were strained against the darkness of the night.

They knew not when they might be surrounded by the armies of the Czar.

A clatter of hoofs out of the obscurity of the night and the sentinels at the gates stood at attention.

It was one o’clock in the morning and the whole town slept.

“Who goes there?” challenged the sentry, as the horsemen drew up at the gate.

There were but two of them, as shown by the lantern beams above the arched entrance.

The foremost answered.

“We are couriers dispatched from Turkey by the King of Sweden,” he said.

The soldier looked at him curiously and saw a tall, powerful-looking man in a gray suit and dark blue mantle, wearing a black peruke and a riding-hat laced with gold.