You may be sure that Rudolf and Ann did not join in the burst of applause which greeted the end of Captain Mittens’ song.  Peter would have been glad to, for he was too young and foolish to understand how really impertinent Mittens had been, but his brother and sister quickly stopped that.  As for Growler and Prowler, they merely yawned, as if they had heard this song more than once before, only faintly clapping their paws together in order not to attract the tyrant’s attention to themselves.  The next piece on the program, so Mittens announced, would be a duet between himself and Miss Tabitha Tortoise, entitled Moonbeams on the Back Fence.  This selection proved so very noisy, so full of quavers, trills, and loud and piercing yowls, that the children decided it would be safe to attempt a little conversation.

“Oh, Rudolf,” whispered Ann, “how shall we ever get away from here?”

“Don’t want to get away,” grumbled Peter.  “We’re going to have refreshments; Mittens said so.”

“Nonsense; you’ll have to go if we do,” answered Rudolf.  “But listen, what are the mates saying?”

The two black cat pirates were conversing excitedly under cover of the music, and presently the children heard what Prowler was whispering to Growler:  “Look here, Matey, where’s the rest of the swag, the suit case and his sword, you know?”

“On board ship, stowed away in Cap’n’s cabin,” answered Growler.  “You don’t mean to—­”

“Yes, I do—­I’m no ’fraid-cat—­I mean to have them pink pajamas, or—­”

“And where do I come in, eh?” exclaimed Growler indignantly.

“Oh, you can have the shirts and collars, Matey.  Share and share alike, you know.  We’ll just slip off to the ship, and—­”

“And take us with you,” broke in Rudolf.  “Do!”

“You know you promised to do us a good turn,” whispered Ann.  “And if you don’t take us we’ll tell, and we’ll tell about what happened to the white mice, too—­”

“And while you’re about it,” went on Rudolf, “you’d better take possession of the vessel.  Between us we can easily manage those old spotties that were left on board.  Then, don’t you see, when you fellows are masters of the Merry Mouser, you’ll have Mittens in your power and you can make him whack up on all the treasure!”

At this brilliant suggestion the two mates gave a smothered cheer, gazing at each other with their round yellow eyes full of joy and their whiskered mouths grinning so widely that the children could see their little red tongues and all their sharp white teeth.

“But how shall we get away without being seen?” Ann asked.

“Oh, that’ll be all right,” said Prowler, looking about him nervously.  “Just wait till you hear ’em announce the refreshments—­that always means a rush, you know.  Then slip through the crowd and out by that door behind the curtain, and hustle down to the ship just as fast as ever you can lay your paws to the ground!”