The girls had crept closer and were near enough to hear what the men said.
The latter seemed to be on the far side of the boathouse. They had evidently neither seen nor heard the girls.
"I tell you, Jim, it was a slick job," came the low, gruff voice of one of the men.
"They are the thieves!" whispered Sadie, and tugged at the arm that was still in Jo's grasp.
"Oh, hush!" cried the latter. "Listen!"
"It sure was," responded a second voice, lighter in timbre and less guarded, as though the speaker were a younger man than his companion. "It was so well done that Miss Romaine thinks it the work of some mischievous girls."
Both men laughed and the girls looked at each other inquiringly.
"That voice doesn't sound like a thief's voice to me," remarked Nan.
"Listen!" cried Jo again.
"The crooks are slick ones and they're probably responsible for some other small robberies in town," came the voice of the first speaker. "But we'll find 'em yet, you bet!"