"Hallo, Gerda! What are you doing here?" called Deirdre, finding speech at last. Gerda dropped Ronnie, and sprang to her feet with a sharp exclamation. No one could have looked more utterly and egregiously caught. She stood staring at the two faces on the top of the wall, and offered no explanation whatever. Ronnie, however, waved his hand merrily. "We've been playing Zoo," he volunteered. "Gerda's been a lion, and gobbled me up, and she's been an elephant and given me rides, and we were both polar bears, and growled at each other. Listen how I can growl now--Ur-ur-ugh! Oh, and look what she's given me for my birthday! It comes from Germany," producing from his pocket a little compass. "Now if ever I get lost, I can always find my way home. See, I can show you which is north, and south, and east, and west." "You'd better be going back, Gerda," remarked Dulcie grimly. "You know we're not allowed in the Castle grounds without a special invitation." "I'll come through the side gate," replied Gerda, turning from Ronnie without even a good-bye. Deirdre and Dulcie dropped from the wall, and met their room-mate at the identical moment when she passed through the turnstile. "Well, of all mean people you're the meanest!" observed Deirdre. "I call it sneaky to take such an advantage, and go to play with Ronnie by yourself. We'd do it if it were allowed, but it isn't." "I wonder his governess wasn't with him," said Dulcie. "He's generally so very much looked after." "And as for going inside the Castle garden, it was most fearful cheek," continued Deirdre. "We, who know Mrs. Trevellyan quite well, never think of doing such a thing." "What I call meanest," put in Dulcie, "was to try and curry favour with Ronnie by giving him a birthday present on your own account. Miss Birks said there were to be no separate presents: we were all to join, so that there'd be no jealousy--and you wouldn't subscribe. Oh, you are a nasty, hole-and-corner, underhand sneak! Have you anything to say for yourself?" But Gerda stumped resolutely along with her hands in her coat pockets, and answered never a word. CHAPTER VIII A Meeting on the Shore "D'you know, Dulcie," remarked Deirdre, when the chums were alone, "the more I think about it, the more convinced I am there's something queer about Gerda Thorwaldson." "So am I," returned Dulcie emphatically. "Something very queer indeed. I never liked her from the first: she always gives me the impression that she's listening and taking mental notes." "For what?" "Ah, that's the question! What?" "I certainly think we ought to be on our guard, and to watch her carefully, only we mustn't on any account let her know what we're doing." "Rather not!" "She's no business to sneak away by herself when we're all salvaging on the beach. She knows perfectly well it's against rules." "She doesn't seem to mind rules."