For they were now tearing up the river at a furious pace. On, on, on—the boat rocking and bounding—often shooting into the air completely when the runners struck a “hubbly” piece of ice—peeling the miles off under the runner-shoes with nerve-racking speed.

Directly they saw the gaunt outline of tree-tops on the right hand. They were passing some island; but which one, neither boy could have told at the moment. The usual landmarks were wiped out.

For what point along the upper reaches of the Colasha were the robbers headed? That was a disturbing query in Dan’s mind. Had the fellows prepared some hide-out for the motor iceboat, even before they had stolen her?

And the puzzle was: What did they want of the Follow Me? Was the robbery merely for the sake of keeping the Speedwell boys out of the regatta—which was now but a week away? Or, was the crime committed for an entirely different reason?

Unless the scoundrels removed the boat from the river it would be rather difficult to hide her for long.

“But they can make us a whole lot of trouble—that’s a dead certainty,” muttered Dan, striving to clear his goggles of the wet and clinging snowflakes.

“D’ye hear anything, Dan?” yelled Billy at that moment.

“Not a thing.”

“Crickey!” cried the younger boy. “Mebbe those fellers have run her under the ice.”

Dan caught most of what his brother said, but only shook his head. Billy, as he stood clinging to the leather hand-hold, was outlined by the snow, which made his figure bulk hugely in the uncertain light.