ight. I'm going to ask one of the stewards where their
stateroom is, and why they don't come out."

"You may get into trouble."

"Oh, I guess not. If I do I can stand it. I want to solve this
mystery." Tom did put his question to one of the dining saloon
stewards and it created no suspicions.

"Ah, yes, I guess you must mean Mr. Wilson and his son." spoke the
steward when he had referred to a list that corresponded with the
numbers of the vacant places at the table. "They have their meals
served in their stateroom."

"Why?" asked Tom, "are they ill?"

"I really couldn't say, sir. They prefer it that way, and the
captain consented to it from the first."

"But I should think they'd want to get out for a breath of air," put
in Ned. "I can't stay below decks very long."

"They may come out at night," suggested the steward. "Some of our
travelers think they are less likely to be seasick if they come out
at night. They don't see the motion of the waves then."

"Guess that's it," agreed Tom with a wink at Ned. "Much obliged.
Glad we're not seasick," and he linked his arm in that of his chum's
and marched him off.

"Why the wink?" asked Ned, when they were out of earshot of the
steward.

"That was to tip you off to say nothing more. I've got a plan I'm
going to work."

"What is it?"

"Well, we know who the mysterious ones are, anyhow--at least we know
their names--Wilson."

"It may not be the right one."

"That doesn't make any difference. I can find out their stateroom by
looking at the passenger list."

"What good will that do."

"Lots. I'm going to keep a watch on that stateroom until I get a
good look at the people in it. And if they only come out at night,
which it begins to look like, I'm going to do some night watching.
This thing has got to be settled, Ned. Our trip to the city of gold
is too important to risk having a mysterious couple on our trail--when
that same couple may be the Fogers. I'm going to do some detective
work, Ned!"

CHAPTER XI

THE MIDNIGHT ALARM

"Whew! What a lot of 'em!"

"Bless my fish line! It's a big school!"

"Look how they turn over and over, and leap from the water."

"By golly, dere is suttinly some fish dere!"

These were the exclamations made by our four friends a few days
later, as they leaned over the rail of the Maderia and watched a big
school of porpoises gamboling about in the warm waters of the gulf
stream. It was the second porpoise school t