Inside the prison the Doctor was swinging his arms to get the stiffness out of them.
"You said something about a message you had for Dab-Dab, I think," peeped the white mouse's voice from the darkness of the corner.
"Yes," said the Doctor—"and a very urgent one. But I don't see how on earth I'm going to get it to her. This place is made of stone and the door's frightfully thick. I noticed it as I came in."
"Don't worry, Doctor, I'll get it to her," said the mouse. "I've just found an old rat hole over here in the corner. I popped down it and it goes under the wall and comes out by the root of the tree on the other side of the road from the prison."
"Oh, how splendid!" cried the Doctor.
"Give me the message," said the white mouse, "and I'll hand it to Dab-Dab before you can say Jack Robinson. She's sitting in the tree, where the hole comes out."
"Tell her," said the Doctor, "to fly over to the Harmattan Rocks right away and give the cormorants strict orders to stop all pearl fishing at once."
"All right," said the mouse. And he slipped down the rat hole.
Dab-Dab, as soon as she got the message, went straight off to the pearl fisheries and gave the Doctor's instructions to the cormorants.
She was only just in time. For the Emir's six special men were about to land on the islands to get a second load of pearls. Dab-Dab and the cormorants swiftly threw back into the sea the oysters that had been fished up and when the Emir's men arrived they found nothing.