Their journey home—that is, to Sark—that day was not entirely without incident. For when they got down to the quay, Sark had disappeared completely, and Herm and Jethou were no more than wan ghosts of their natural selves, in a dense white mist.

"Ah-ha! Here is our old friend of Tintageu," said Graeme jovially. "Well, I must confess to bearing him no ill-feeling—if he doesn\'t land us on a rock this time. Going, captain?"

"Oh yess, we go. I think it will lift," said Captain Bichard.

"Don\'t run us on a rock anyway."

"I won\'d run you on no rock. I coult smell my way across;" and they started, feeling their way cautiously past Castle Cornet, into the open, where black jaws lined with white teeth lie in wait for the unwary.

And just as they got to the south of Jethou they saw a sight the like of which none of them had ever seen before, nor, from the exclamations about them, had any of the rest.

The mist in front was like a soft white curtain, and upon it, straight ahead of their bows, appeared suddenly a mighty silver bow, not a rainbow, because there was no rain and so there were no colours. But, like the bow they had seen from Belême Cliff, this also was a perfect circle, all but a tiny segment where it appeared to rest upon the sea, and its only colour was a dazzling silvery sheen which waxed as they watched it in breathless silence. Then it waned, bit by bit, till at last it was gone, and only the white mist curtain remained.

"How very lovely!" murmured Margaret.

"A good omen for certain," said Miss Penny. "Even Johnnie Vautrin couldn\'t make any ill news out of that. It was your wedding arch, Meg."

"Well, that\'s the first time I ever saw a white rainbow," said Graeme to the captain.

"First time I ever saw one myself, sir."

"Not very common then."

"Never heard of one before."

"We\'re evidently in............