Tahu sat a while on the rocks, cutting the surface of the water with his stick, and dreaming summer dreams. When the sun began to burn the back of his neck he stood up, took a very big breath and dived deep into the pool. He swam as far down as he could and came up gasping and rubbing the stinging water from his eyes. He was about to climb out for a second dive when his heart gave a little jump of surprise. Seated on the diving-rock, his feet in the cool water, was an old man! ‘Where did you come from?’ asked Tahu. He realised at once that he must sound rude, but he could not understand how he had failed to see the old fellow arriving. The man smiled down at the boy and Tahu saw that many wrinkles lined his cheeks. His chin was covered with a snowy beard, and his hair too was snow-white. ‘E tama, tena koe,’ he said. Tahu scrambled out and greeted the man in a manner more befitting his great age. He could not help adding: ‘You don't come from around here, do you?’ ‘I do,’ said the old one, ‘but hardly anyone ever sees me.’ It seemed an odd answer, and Tahu thought the old man looked sad in spite of his pleasant smile. ‘Tell me, boy, can you dive to the bottom?’ ‘Nobody can do that,’ said Tahu. ‘We have all tried, and so has our father, but we think there is no bottom to this pool.’ ‘Of course there is,’ said the old man. ‘I can show it to you. Here! Hold this in your left hand and take my hand in your right, and we shall find it together.’ Tahu looked down. In his palm lay the most perfectly-shaped pendant. It was the clearest piece of tangiwai greenstone, like a huge green teardrop, and smooth as glass. He looked at it a long time, wondering what he should do. ‘If I dive with you, shall I come up again?’ ‘For sure! You have only to drop the greenstone and you'll pop up again like a stick of whau.’ ‘Come on, then,’ said Tahu, grasping the old hand and taking in a deep gulp of air before plunging into the depths of the pool. The old man's fingers were rough, but Tahu held on firmly. He felt himself being dragged at tremendous speed. When he opened his eyes he could see only murky darkness. Soon he felt soft sand beneath him, but the horny hand dragged him on. He was not afraid now and his breath seemed to last wonderfully well. Suddenly they were travelling upwards and the water around them was growing light. A couple of kicks brought him to the surface. Tahu saw that they were in some sort of cave. High above, through a cleft, he could see a tiny patch of sky. The rest was rock, and swirling, roaring sea water. He had no time to see more for the old man was tugging at his hand again. As they dived the water seemed to crash and surge all around them, yet they cut through it like porpoises. Soon the roaring ceased, the sea became calm and paler again, and they were swimming more slowly. Tahu's head broke the surface just as the old man's hand let his loose. He swam on, still clutching the pendant. He was making for a tiny golden beach that lay ahead. Above the shoreline, tall pohutukawas twisted, and beyond, he could see on the flat, an old-style Maori whare. The old man had reached the shore first and was waiting on the sand. ‘Do you know where you are?’ he asked. Tahu knew that he had not come far from home, but that he had never been in this spot before. Looking out over the sea he thought he could make out, away to the north, the familiar headland that formed part of the view from his bedroom window. He could not remember having seen it from this angle, yet he knew the hills and shore like the back of his hand. There was only one place he could be. Nobody he knew had ever visited it. He was almost afraid to ask. ‘Am I on the tapu island?’ he said at last. ‘That's right. We are on Motu-tapu.’ ‘But I'm not allowed here! There is a taniwha here—and—and—bad things will happen.’ Tahu was alarmed. ‘No, boy! No. Do not be afraid,’ said the old man soothingly. ‘No bad things are here today. Did not the greenstone protect you through the breakers and in the cave, and bring you safely here?’ ‘Yes, I suppose it did,’ Tahu answered. ‘Then you are safe here too,’ said the old man. ‘Look. That is my house over there. Does it look like a house of bad things?’ ‘No, but it looks awfully old: too old to be real.’ The old man laughed. ‘Listen,’ he said, ‘I shall tell you a story, and you will understand all … ‘… Long ago, when first the Maori people came to these parts, many taniwha lived in the sea and in the rivers. There was much