"I wonder what sort of a craft they are in?" queried Harry.
"It can't be either a rowboat or a launch," replied the old detective, "and it is hard to see how they can get around with a sailboat on a night like this, yet that must be what it is."
"There is a breeze springing up now," observed the kicker.
He had scarcely spoken when the voices were heard close to them.
Evidently the ebb tide was taking the smugglers, if such they were, their way.
They were now speaking loud and rapidly.
"Draw your revolvers, boys, and be ready," breathed Old King Brady. "We are liable to be discovered at any moment."
Alice sat listening.
"They are the smugglers, all right," she presently whispered.
"Sure?" asked Old King Brady.
"Yes. They say – "
"Never mind, Alice, unless it is something important."
Still the voices continued.
The smugglers appeared to be passing the launch in the direction of the channel.
"Listen!" whispered Alice, as they presently ceased. "This is important. One said: 'We must hurry if we expect to save the princess. She can't stand it much longer.'"
"What can that mean?"
"The name of their boat, perhaps."
"Do you think so?"
"Frankly, I don't. It seemed to me as if they were speaking of a person."
"Then they must have a woman with them. Perhaps some Chinese woman they are smuggling in."
Suddenly a loud voice exclaimed in English: "Here's your channel now, you Chinks!"
"Allee light! Allee light! Hully up now," came the reply.
The breeze had increased. The fog was lifting a little. Certain sounds were heard that indicated a sailboat going about.
"Shall I start up?" asked Harry.
"Not yet," was the reply. "Let them get well into the channel, then we will close in on them."
The voices died away; the time to move had come.
"Now," said Old King Brady. Immediately the "chug-chug" of the motor made itself heard.
"Bear right down upon them," ordered the old detective; "a little brisk action will put us on the right side of this outfit, I hope. Alice, you get down in the boat."
Alice, brave girl that she is, protested that she was willing to take her chances with the rest, but Old King Brady sternly repeating the order, it was obeyed.
A few moments of anxious suspense and a large sailboat loomed up out of the mist right ahead of them.
Instantly Old King Brady turned a powerful electric flashlight upon it.
In the boat were several boxes and bales. One box seemed particularly large.
If this was filled with opium, Old King Brady knew that it must be very valuable.
There were three Chinamen in the boat and one white man.
"Lower your sail and surrender!" thundered Old King Brady.
The white man appeared about to obey, but one of the Chinamen interfered.
The other two immediately discharged their revolvers at the launch.
The shots flew harmlessly past them, but it made the old detective vexed to think that he had not been the first to open fire, which he and the others by his command now instantly did.
Whether any one was hit or not it was impossible to tell, but all four men at once sprang overboard and, abandoning their boat, struck out for the south bulkhead of the channel, which was no great distance away.
"We win!" cried the old detective. "No more firing, boys. I had just as soon they would escape."
They pushed on to the abandoned boat.
The mist closed in on them and the swimmers were lost to view.
Making fast to the boat, the kicker sprang aboard and lowered the sail.
"A good haul, Mr. Brady," he exclaimed. "There are thousands of pounds of hop here, but what do you suppose is in this big box?"
"That remains for us to discover," replied Old King Brady. "Is it heavy?"
"Very," replied the kicker, weighting the box.
"Never mind now. Make fast and we will pull around to the Indian Basin. I shall touch nothing until we are at the Government stores."
The kicker obeyed, and was just about to step back into the launch, when Old King Brady, ordering him to remain where he was, he sat down on the big tin box.
Instantly he jumped up again, exclaiming:
"Good heavens! There is some one alive in this box!"
"Ah! The princess!" cried Alice.
"What did you hear?" demanded Old King Brady.
"Some one spoke. There it goes again! It's a Chinaman."
"Or a woman! Alice, do you think you can get aboard the sailboat without tumbling into the bay?"
"Why, certainly," replied Alice, and she stepped aboard the sailboat with the kicker's aid.
"Is any one in the box?" she called.
"Yes. Help! Save me! I am dying in here!" came the answer in Chinese.
Alice instantly repeated the words.
"We must make a landing right here on the bulkhead in front of these warehouses," declared Old King Brady, and he gave Harry orders accordingly.
Loaded down as the sailboat was, it would have been both difficult and dangerous to attempt to open the bulky box on board.
Indeed, in order to get at it properly, a good portion of the contents of the boat would have to be removed in any case.
"Ask her who she is and how she came to be there, Alice," the old detective called; adding:
"I am assuming that it is a woman."
"Yes, it's a woman," replied Alice, and she put the question.
"She says she is the Princess Skeep Hup," Alice called.
"Ask her how she came to be in the box."
But when Alice put the question there came no reply.
"I'm afraid she has fainted!" said Alice, "or, indeed, she may be dead."
"A mystery!" cried Harry. "The mystery that came out of the mist."
CHAPTER II.
ALICE AND THE CHINESE PRINCESS
To make a quick opening of the box containing the Chinese Princess was quite impossible.
Besides the difficulties already explained, there were others.
The box was not nailed.
Examination showed that it was put together with screws, and that the boards were of some hard wood.
Air-holes bored in the sides at regular intervals showed that the imprisoned princess certainly ought to have no difficulty in breathing, and made it seem that her present unconsciousness was probably nothing more than a faint.
The landing at the bulkhead had now been made.
There appeared to be no watchman here – at least no one challenged the Secret Service party.
Behind the bulkhead extended a row of storage warehouses.
The boat had been tied up opposite a break in this row formed by a street extending back towards Amador street, the first of which parallels the Islais Creek Channel on the south.
The Bradys had plenty