othing does happen to us or to our boat."

"Are you goin' to take them girls along that you had yesterday?"
inquired Sam abruptly.

"Do you mean in the race?" asked Fred.

"What did you think I meant?"

"Well, we're not going to take them."

"Then maybe there'll be a chance to win out. I wouldn't promise
anything with them on board, especially one of them. She's all right,
but she would want to steer the boat and talk to the crew when it might
be that the whole race was dependin' on what we were doin' right then
and there."

"No, you can rest easy about that," said Fred. "There won't be anybody
on board except the Go Ahead boys and you."

"Well, then," said Sam, "if that's the case then we'll have to keep a
sharp watch on the Black Growler."

Sam's manner more than the words he spoke impressed the boys with the
fact that he was holding back something that he had heard or knew
concerning the possibilities of trouble for the swift little
motor-boat. Just what they were, neither Fred nor George could
conjecture. Their confidence in Sam was great and when they departed
from the boat-house they made light of his fears.

"Sam is a regular old kill joy," laughed George.

"There has to be somebody," said Fred, "to take the joy out of life. It
wouldn't be worth living if that wasn't so."

"Well, Sam does his best," said George with a laugh, "and the only
reason why he doesn't succeed is because his bark is worse than his
bite. We know he doesn't mean half he says."

"But why does he seem so worried about something happening to the Black
Growler?"

"Oh, I don't know," said George. "That's just one of his notions, I
guess."

It was not long, however, before both boys were excitedly aware that
Sam's forebodings had been based upon a knowledge greater than that
possessed by any of the Go Ahead boys.

CHAPTER XXI

THE SUMMONS IN THE NIGHT

On each of the three days that followed, the Black Growler was sent
over a part of the course which had been mapped out for the race. The
speed of the marvelous little motor-boat apparently was satisfactory to
all concerned, except Sam. He growled and protested that there was
something wrong with the boat and declared that unless they kept a
careful watch, other things that would be still worse might occur.

On several occasions an impromptu race was had with the Varmint II. It
was plain to the occupants of each boat that their rival was dangerous.
Fred became more anxi