Like a flash he was at the window, peering out.

Where, after all, was the cat's vision of which he had thought himself possessed?
Some one was outside the window.

Dave thought he recognized the Naval uniform, but he could not see a line of the face.
Tap-tap-tap! sounded softly.

Dave threw the window up stealthily.
"You, Dan ?" he whispered.
"Of course," came the soft answer.

"Stand aside.