"I wouldn't be too sure," muttered Jack to Frank. "She may be flying the English flag and still be an enemy. I don't trust these Germans much."
"Nor I," agreed Frank. "However, we will soon know whether she is friend or foe."
Slowly the cruiser drew nearer. Now the boys were able to make out the British flag flying at her masthead. There came a puff of smoke from the stranger, and a shot passed over the bow of the Lena.
"Signal to show our colors," muttered Frank.
At his command the British ensign soon fluttered gaily in the breeze.
Came another shot from the cruiser.
"What's the matter now, do you suppose?" asked Frank. "That's a signal to heave to. If she's British, what does she want us to heave to for?"
The vessels were still a considerable distance apart, and night was drawing on. The answer to Frank's question came from the approaching vessel.
The British ensign flying at the masthead of the approaching cruiser suddenly came fluttering down, and a moment later the Red, white and Black of Germany fluttered aloft in its stead.
"By Jove!" exclaimed Jack. "I was afraid of it!"