In five miles we saw no rift or break. And then suddenly we perceived something which filled us with new hope. In a hollow of the rock, protected from rain, there was drawn a rough arrow in chalk, pointing still to the westwards.

“Maple White again,” said Professor Challenger. “He had some presentiment that worthy footsteps would follow close behind him.”

“He had chalk, then?”

“A box of colored chalks was among the effects I found in his knapsack. I remember that the white one was worn to a stump.”

“That is certainly good evidence,” said Summerlee. “We can only accept his guidance and follow on to the westward.”