"How do you make that out?" queried the wondering cowboy.
"Why, a bigger volume of sound, distance considered, than the Sprite makes. I noticed that particularly when we were chasing the San Bruno across the bay."
"Well, you've got me beat, plumb. We've got to swim, I reckon, going off one side of the house boat as the launch ties up at the other?"
"We'll not take to the water until we have to, Joe. Wait until we can get a good look at the boat."
Standing on the upper deck, the two boys faced in the direction of the approaching launch, and waited and worried.
Slowly, and after a period of time that seemed interminable, a blot of shadow came gliding toward them from among the clustered lights of the house boats.
Matt whirled to grip McGlory's arm.
"What's to pay now, pard?" asked the startled cowboy.
"Why," answered Matt, "two boats are coming!"
"Two?" echoed McGlory, squinting in the direction of the moving blot. "I can't make out more than one, and it's plenty hard to see that."