In two hours’ time four small rafts of the horrible-smelling cork were made. They looked rather queer and they smelt even queerer, but they floated marvellously, bobbing about on the water like strange ducks. The children were delighted. It was going to be splendid fun to float down the hidden river, under a green archway of trees, right up to the Secret Mountain!

“Our guide says that his tribe always use these queer rafts to get quickly down this valley, which they fear because of the Mountain Folk,” said Ranni. “The stream goes right round the foot of the Secret Mountain, and joins a river round there. Then it goes into the next valley, which is a fine hunting-ground used by Mafumu’s tribe. He says that the rafts don’t last long — they gradually fall to bits — but last just long enough to take a man into the next valley with safety!”

Pilescu and Paul got on to one raft. It wobbled dangerously, but sank hardly at all into the water. There was only just room for the two of them to squat. They held on to the creeper-ropes that bound the raft together. Then down the stream they went, bobbing like corks.

Ranni and Nora went next. Mike and Peggy went together, and last of all came the guide, Jack, and, of course, Mafumu, who was determined not to leave Jack for even a minute!

It was a strange journey, a little frightening. The trees met overhead and were so thick that no sunlight pierced through to the swift stream. The only light there was glowed a dim green.

“Your face looks green!” cried Peggy to Mike, as they set off together down the strange river-tunnel.

“So does yours!” said Mike. “Everything looks green. I feel as if we must be under water! It’s because we can’t see any daylight at all — only the green of the trees and of the stream below.”

The stream became swifter as it ran down the valley. In no place did the trees break — the tunnel was complete the whole way. The rafts were really splendid, but towards the end of the journey they began to break up a little. The outside edges fell off, and the rafts began to loosen from the creeper-ropes.

“Hie! We shall soon be in the water!” yelled Ranni. “Where do we land?”

The guide shouted something back. “Well, that’s a good thing!” cried Ranni. “We’re nearly there, children.”