Poor Eradicate did suffer though.  He was very seasick, and kept to his berth most of the time, while some of his new friends did what they could for him.

Tom had in mind a plan whereby he might solve the identity of the mysterious passengers.  He was going to do it by a process of elimination—­that is he would carefully note all on board until he had fixed on the two who had aroused his suspicions.  And he had to do this because so many of the passengers looked very different, now that they had on their ship “togs,” than when first coming on board.

But the rough weather of the first day prevented the lad from carrying out his plan, as many of the travelers kept to their staterooms, and there were a score of vacant places at the tables.

The next day, however, was fine, and with the sea like the proverbial mill pond, it seemed that everyone was out on deck.  Yet when meal time came there were these same two vacant seats.

“What do you think of it, Ned?” asked Tom, with a puzzled air.

“I don’t know what to think, Tom.  It sure is queer that these two—­ whoever they are—­don’t ever come to meals.  They can’t be seasick on a day like this, and they certainly weren’t the first night.”

“That’s right.  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.”