Pulling the brass chain, she opened it, and peered out onto the dark roof. No one was in sight. In the adjoining building, lights burned in a number of offices.

Suddenly the door of the photography room opened. Startled, Penny ducked down so fast that she bumped her head.

“Well, for Pete’s sake!” exclaimed a familiar voice. “What are you doing up there?”

Penny was relieved to recognize Salt. She closed the skylight and dropped lightly to the floor.

“Looking for termites?” the photographer asked.

“Two legged ones! Salt, someone has been prowling about in here! Whoever he was, he came in through this skylight.”

“What makes you think so, kitten?” Salt looked mildly amused and not in the least convinced.

Penny told him what had happened and showed him the footprints on the filing cabinet. Only then did the photographer take her seriously.

“Well, this is something!” he exclaimed. “But who would sneak in here and for what reason?”

“Do you have anything valuable in the darkroom?”