"Then a perfectly criss-cross one, all black and red and yellow and blue!" said Joan.
"That's Zed," said Garth. "What's the bottom one? Oh, I see it now; it's Unit."
"MZU," Joan cried, seizing the code again. "I have it! Require water for drinking and cooking. This is the most exciting thing I've ever done!"
"There goes the Billington, answering her," said Garth. "That's almost like the other one. Mike—Zed, and I think the bottom is Rush—a red square inside a white one, with a blue border, Joan."
"No, that's Watch," she told him, consulting the pictured flags in the book. "MZW: Will send you water. Oh, how nice; they'll have their water, then!"
There ensued a pause when the signaling stopped, and Joan feverishly studied the code, trying to memorize the shapes and colors of the flags and their outlandish names. For this reason she did not see a hoist go up aboard the Billington, till Garth suddenly shouted:
"Easy—Pup—Yoke!"
"How perfectly absurd!" laughed Joan. "Why did they pick out such ridiculous words?
