"Now to get back to Bayport," whispered Frank. "We'll have to hurry."
They sped across the grass toward the borders of the dark wood, and not until they had reached its friendly shade did they look behind. The ghostly old mill stood by the gleaming river, dark and sinister in the clear moonlight.
"We'll be back," Joe said, as he glanced back at the mill.
"There is going to be a big surprise for that gang before the night is over."
"I'll say. Let's get started on it."
They ran up through the trees until they reached the deserted road, where they had left their motorcycles. Within a few minutes they were in the saddles and roaring back in the direction of Bayport.
They made the journey at full speed, but at that it was late before the gleaming lights of the city came into view. The motorcycles sped down the shore road on to the concrete boulevards, then raced through the city streets, now almost deserted save for an occasional late trolley or nighthawk taxi.
At length they drew up before the Hardy home and raced up the front walk. They found their father in the house, sitting up for them.
"What on earth kept you out so late? Your mother—" Fenton Hardy began, but Frank interrupted him.
"We've found the counterfeiters!"