All right," he called out to P.C.Roper, who was getting anxious, "we're just coming." Then Janet had a happy thought.

"I say," she exclaimed, "where is that envelope that Uncle Christopher gave us?
He said we were to open it if we got into a real mess.

Well, now's the time." "It's in the safe," said Robert, and he dashed into the caravan and brought it out.
Janet opened it and read it slowly.

Then she smiled a radiant smile, and, advancing to the constable, handed him a paper.
"Here is the license," she said; "you will find our name and address on it.

Now, perhaps, we may go on." P.C.Roper read the license very carefully, frowned, and handed it back.
"It would save a lot of trouble," he said, "if you would produce such things directly you were asked for them." "But we didn't know we'd got it," Janet said.
P.C.Roper pressed his hand to his forehead.