Frank bowed but said nothing.

Half an hour later he was conducted to a cell at the end of the fort nearest the outer wall. Here he sat all day, being well treated and well fed, but allowed no liberty.

“By George!” said Frank to himself right after noon, “I have a notion to try to get out of here. I don’t know whether I can get away or not, but I believe I shall take a chance at it. I don’t want to be cooped up in Berlin for the next few years if I can help it.”

Accordingly he mapped out a plan, which he decided to put into execution when the jailer brought his evening meal.

The afternoon passed slowly, but at length the time to act came.

A key grated in the cell door and the jailer entered, carrying a tray of food.

“How is the weather outside?” asked Frank.

The jailer was a jovial sort.

“Fine,” he replied. “Too bad you cannot be out to enjoy it.”

“It is too bad,” Frank agreed. “Well, what do I get for supper?” and he bent over as though to examine the tray.