Frank, "and those are sailors who are
singing. We are not alone in the Everglades."

"They're all drunk," declared the professor. "You can tell that by the
sound of their voices. Drunken men are dangerous."

"They're a blamed soight betther than none, fer it's loikely they know
th' way out av this blissed swamp," said Barney.

"They may bub-bub-be pup-pup-pup-pirates!" chattered the professor.

"What sticks me," said Frank, "is how a party of sailors ever made their
way in here, for we are miles upon miles from the coast. Here is another
mystery."

"Are ye fer takin' a look at th' loikes av thim, Frankie?"

"Certainly, and that without delay. Come, professor."

"Never!"

"What do you mean?"

"I am not going near those ruffianly and bloodthirsty pirates."

"Then you may stay here with the spooks, while Barney and I go."

This was altogether too much for the professor, and, when he found they
really intended to go, he gave in.

Frank loaded the rifles and the shotgun, and took along his bow and
arrows, even though Barney made sport of him for bothering with the
last.

They slipped the canoe into the water, and, directed by Frank, the
professor succeeded in getting in without upsetting the frail affair.

"Oi hope we won't run inther the ghost," uttered the Irish boy.

"The sound of that singing comes from the direction in which the old man
seemed to point," said Frank.

This was true, as they all remembered.

The singing continued, sometimes sinking to a low, droning sound,
sometimes rising to a wild wail that sounded weirdly over the marshland.

"Ready," said Frank, and the canoe slipped silently over the dark
surface of the water course.

The singing ceased after a time, but they were still guided by the sound
of wrangling voices.

"They are quarreling!" exclaimed Frank, softly.

"This is tut-tut-terrible!" stuttered the professor.

Suddenly the sound of a pistol shot came over the rushes, followed by a
feminine shriek of pain or terror!

CHAPTER XXX.

FRANK'S SHOT.

Frank and his two companions were profoundly astonished. As soon as he
could recover, Frank asked:

"Did you hear that?"

"Av course we hearrud it!" returned Barney, excitedly.

"It sounded very much like the voice of a woman or girl," said Professor
Scotch, who was so amazed that he forgot for the moment that he was
scared.

"That's what it was," declared Frank; "and it means that our aid is
needed in that quar