For hours, Pat and Algy force their way through the unbelievable growth of the rain forest. The massive trees are linked with the nightmare tangle of vegetation, and it resists them, tears at them, and clings to them until their muscles ache and the perspiration streams from their bodies. At midday they halt, as neither can go on without rest. They clambor across to a tiny brook, with is an oasis of beauty after the horror of the forest, but they're not alone...