something that the trees and vines protested against.

But in spite of the strange melancholy of the place, the two girls were
in much better spirits than they had been on the previous day. The
successful passage over the ledge had brought about a reaction, and a
remark of Holman's caused Barbara Herndon to laugh with all the
spontaneity that was noticeable upon _The Waif_. The effect of that
ripple of laughter was startling. The sound rebounded from the rocky
cliffs, cannoned against the barriers opposite, and then bounced
backward and forward till the whole atmosphere of the valley seemed
alive with the laughter of sprites. For quite five minutes we stood
listening, then the silence chased the last faint echoes out across the
cliffs, and we breathed again.

"It is the Valley of Echoes," said Leith. "The cliffs throw back the
sound in a marvellous manner."

"I'll not laugh again, not in this spot," murmured Barbara Herndon.
"Those noises chilled my blood."

In spite of a blazing sun we found the air unpleasantly cool in the
shaded spots as we struggled slowly through the undergrowth. The moist
flabbiness of uncommon tropical plants startled us whenever the leaves
brushed against our faces and hands, while the constant popping of the
green pods of the nupu, the sounds resembling nothing so much as the
groans of a person in extreme pain, did not have a cheering effect upon
the party. The Professor was the only one who seemed to be actually
enjoying himself, and even his joy was tempered by a malignant Fate.
While endeavouring to dot down some information tendered him by Soma, he
had tripped upon a vine that was in wait for such an opportunity, and