"I never had a grandmother," Serena said, "Not a single one. Not a mother, not a brother, not a sister, not a cousin. In fact, there was a general drought of relatives where I was concerned. A long dry spell. Although once I brought home a kitten, and my father let me keep it for a while. That kitten was the only relative who ever purely loved me. Does your grandmother love you?"

"I guess," Jasper said. "We have the same ears. That's what everyone says. But I have my father's crummy teeth."

"My father's dead," Serena said, "and so is the kitten."

"I'm sorry," Jasper said, and Serena shrugged. She held her left hand away from her, examining her drawing. It looked like a map to Jasper – pointy stick-drawings of mountains, and lines for roads. She stuck a finger in her mouth and began to smudge the lines away carefully, one by one. "Your ears aren't so bad," she said.

The radio went on and off in a blur of static. Unseasonable weather… party of trekkers on the Milford Track… missing for nearly… between Dumpling and Doughboy Huts… rescue teams… Then nothing but static. Jasper turned off the radio.

"They might as well give up," Serena said. "They're all dead by now, buried under an avalanche somewhere. They'll find the bodies in a couple of weeks when the snow melts." She sounded almost cheerful.

There were tall drifts of snow on either side of the road. Every 500 meters they passed black-and-yellow signs reading: "Danger! Avalanche Area: Do Not Stop Vehicle!" Every sign said exactly the same thing, but Serena read them out loud anyway, in different voices – Elmer Fudd, Humphrey Bogart, the barman's flirty New Zealand sing-song.

"Danger, Will Robinson Crusoe!" she said, "Killer robots and tsunamis from Mars ahead. Also German tourists. Do not stop your vehicle. Do not roll down your window to feed the lions. Remain inside your vehicle at all times. Do not pass go. Do not pick up hitchhikers-oops, too late."

All day the sky had been the color of a blue china plate, flat and suspended upon the narrow teeth of the mountains. The road wound precariously between the mountains, and the car threaded the road. The sun was going down. Just where the road seemed about to lift over the broken mountain rim, where the sun was sliding down to meet them, a black pinprick marked the tunnel into Milford Sound. As Jasper drove, the pinprick became a door and the door became a mouth that ate up first the road and then the car.

Serena was reading out of Jasper's guidebook. "Started in 1935," she said. "Did you know it took twenty years to complete? It's almost a mile long. Four men died in rock falls during the blasting. You should always call a mountain Grandmother, to show respect. Did you know that? Turn on the headlights -"

They went from the pink-gray of the snowdrifts into sudden dark. The road went up at a 45-degree angle, the car laboring against the steep climb. The headlights were sullen and small reflecting off the greasy black swell of the tunnel walls. The walls were not smooth; they bulged and pressed against the tarmac road.

In the headlights, the walls ran with condensation. Over the noise of the car Jasper could hear the plink-plink of fat droplets falling down the black rock. He touched his tongue to his tooth.

"Why, Grandmother, what a big dark tunnel you have," he said. The terrible weight of the mountain above him, the white snow shrouding the black mountain, the stale wet air in the tunnel, all pressed down inexorably upon him in the dark. He felt strangely sad, he felt lost, he felt dizzy. He sank like a slow stone in a cold well.

"Hello sailor," Serena said. "Welcome to Grandmother's Tunnel of Love." She put her long white hand on his leg and looked at him sidelong. He sank down, was pressed down, heavy. His tooth whining like a dog. He couldn't bear the weight of Serena's black eyes, her thin shining face. "Are you all right?"

He shook his head. "Claustrophobic," he managed to say. He could hardly keep his foot on the gas pedal. He saw them spinning through the dark towards a black wall, a frozen door of ice.

And then he had to stop the car. "You drive," he said, and fumbled the door open and went stumbling over to the passenger's door. Serena shifted to the driver's side and he sat down in her warm seat. It took all his strength to shut the door again.

"Please," he said. "Hurry."

She drove competently, talking at him the whole time. "You never told me you were claustrophobic. Lucky for you I came along. We should be out soon."

They came out into night. There was nothing to distinguish one darkness from the other but dirty snow in the headlights. Yet Jasper felt the great clinging weight fall away from him. His tongue went up to touch his broody tooth. "Stop the car," he said. He threw up kneeling beside the road. When he stood up, his knees were wet with melted snow. "I think I'm all right again," he said.

"You drive if you want to," she said. "Your call, pal. It's about another forty-five minutes to the hotel, and you can't miss it. There's only one road and one hotel."

Iced pinecones shattered like glass under the wheels of the car. The road was steeper, circling down this time.

"What does the guidebook say about the hotel?" he asked.

Serena said, "Well, it's an interesting story. This is funny. When I called to make the reservation, the man said they were booked solid. It's a private party or something. But I talked sweet, told him we had come a long way, a really long way." She stuck her feet up on the dashboard and leaned her head on his shoulder. He could see her in the mirror, looking pleased with herself.

Jasper said, "The hotel is full?" He pulled over to the side of the road and put his head against the steering wheel. Serena said, "This is the third time you've stopped the car. I have to pee."

"Is the hotel full or isn't it?" Jasper said.

"Have some chewing gum," Serena said. "Your breath smells like vomit. Don't worry so much."

He couldn't chew the gum, but he sucked on it. He started the car again.

"Is your tooth killing you?" she said.

"Yeah," he said. "Revenge of the sugar cereal."

They went another five hundred yards when something ran across the road. It looked like a small person, scrambling across the road on all fours. It had a long bony tail. Jasper slammed on the brakes and swerved. Serena's arm flailed out and walloped him, catching his jaw precisely upon the broken tooth. He howled. Serena fell forward, knocking her skull loudly against the dashboard. The car came to a stop, and after a moment, during which neither of them was capable of speech, he said, "Are you okay? Did we hit it?"

"What was it?" she said. "A possum? My head hurts. And my hand."

"It wasn't a possum," he said. "Too big. Maybe a deer."

"There are no deer in New Zealand," she said. "The only native mammal is the bat. It's just us poor unsuspecting marsupials around here. Marsupials."

Then she snorted. He was amazed to see that tears were streaming down her face. She was laughing so hard she couldn't speak. "What's a marsupial?" he said. "Are you laughing at me? What's so funny?"

She punched his shoulder. "A possum is a marsupial. It carries its young in a pouch. It's just the word marsupial. It always cracks me up. It's like pantyhose or crumhorn."

It didn't seem that funny to him, but he laughed experimentally. "Marsupial," he said. "Ha."

"Your mouth is bleeding," she said, and snorted again. "Here." She took a dirty Kleenex out of her bag and licked it. Then she applied it to his lower lip. "Let me drive."

"Maybe it was a dog," he said. There was nothing on the road now.

2. Arrival

Milford Sound curls twenty-two kilometers inland, like a dropped boot. Its heel points north, kicking at the belly of South Island. The Tasman Sea fills the boot, slippery and cold and dark. Abel Tasman, the first European to set foot on shore, sailed away in a hurry again after several of his crew were cooked and eaten. He left behind him Breaksea, Doubtful and George Sounds, and Milford Sound, which is now accessible by sea, by air, by foot across the Milford Track, or along the Milford Road by car, through Homer Tunnel.