AT NIGHT, WHEN it was very dark, the light above the door of Dr. Cochrane’s house came on with a surprised pop. A moment or two later, in the time it took for the lamp to collect a couple of flapping, circling, singeing moths, Dr. Cochrane appeared at the top of the outside stair. Dr. Cochrane hated the dark. He came down the stairs to the street like the old man he was, leaning forward to find the next step with his cane, pressing down heavily on the broad stone balustrade with the other hand.

Dr. Cochrane got into his car, laid his cane on the passenger seat at his side and let out the handbrake. He rolled down the hill, gradually gathering speed, moving almost silently until, just before the bend, he turned the key, started the engine and dropped the clutch. Then he flicked the knob that lit the headlights and drove quickly—but not so quickly as to attract attention—onto the road that took him toward the highway along the side of the Merino. The streets were quiet and there was very little traffic at that time of night. Dr. Cochrane drove toward the center of the city, to the places where it was never quiet and the roar of passing cars never ceased. The road grew into huge humpback hills, rose on gigantic concrete legs. Down below, beautiful houses where merchants and sea captains once lived had run aground on tiny green islands, washed up there in an endless, uncrossable tide of traffic and abandoned until the very poorest found them and rowed out to them in desperate flotillas of supermarket trolleys to huddle inside and pick over the wreck. Down there, behind dirty, broken windows, a light showed here and there. Fires burned on concrete slabs under the throbbing, thundering shelter of highway bridges, dancing shadows leapt, dogs trotted. Men who had once been babies, washed and kissed and nestled in blankets, slept in huts made from folded cardboard boxes, lying on mats of newspaper while overhead, where the sky should be, where the stars were blotted out, the traffic drummed and susurrated with the endless rhythm of the hive.

Dr. Cochrane drove on and on until he found himself caught up in a shoal of other cars, a lorry lumbering ahead of him, bouncing and squeaking, shedding gritty dust as it rolled, taxis honking and jostling on either side. He switched lanes, jerking the wheel suddenly to the left, ignoring the blare of horns. He tore across two lanes of traffic, the engine roaring as he surged forward, checked his mirror and swung back across the traffic again, right under the wheels of a sixteen-wheel lorry loaded down with a muddy bulldozer and blazing along its length with a galaxy of twinkling lights. Headlamps flared in his mirror. He pressed his foot to the floor and bounced up the exit ramp that loomed ahead of him, slowing for the curve, checking his mirror again, checking, checking, slowing, turning and following the signs that took him back to the highway, on the other side, back into the stream of traffic, heading the other way.

Dr. Cochrane drove for two junctions, switching lanes, always watching in his mirror until he was sure that there was nobody following and then, without indicating, he turned down the slip road that opened in front of him.

The road swung down to a junction where there was a signpost that he could not read because the light above it was broken and hanging loose. Dr. Cochrane knew the way. He made another right turn into a little square filled with street lamps. There were stalls selling fried food, shops with newspapers hanging down the front of them like lines of washing where they sold cigarettes and sweets and pulp novels, desperate, envious magazines filled with endlessly repeated images of the telenovela stars and Loteria booths scattered round like lifeboats come to offer rescue.

Dr. Cochrane found a place to park down a side street, locked his car and walked back to the square, measuring his way with his cane. He knew the way to the bus stop where the No. 73 would leave from, and when the bus came he threw down his few centavos and sat on the bench seat at the back.

The darkened windows looked back at him blankly. There was nothing to show him where he was, no landmark to guide his journey. He simply sat quietly, saying nothing to anybody, his hands resting on his cane, turning now and then to glance out the big back window and watch for lights following. There were none.

After two stops, nobody else got on. After five stops people started to get off. The bus lurched and stuttered and roared, the gearbox ground. There was a hot smell of diesel oil and Dr. Cochrane’s seasickness returned horribly. After eleven stops there was no one else left on board except for a tall, thin man in a dirty blue jacket sitting halfway down the bus on the right-hand side. Dr. Cochrane had watched him carefully since he joined the bus, when it was crowded and he had been forced to fold himself into a narrow seat over the wheel arch. Now the bus was empty but he had not moved. He sat there with his knees jammed against the polished brass handrail of the seat in front, his head rolling against the window.

Dr. Cochrane slid quietly across his bench seat. It changed the angle between him and the tall man and let him use the dark window as a mirror. He could see the tall man’s face in the reflection. His eyes were shut and Dr. Cochrane did not recognize him.

The bus gave a lurch as it turned a corner and the tall man woke up. He hurried to the front of the bus, swinging from pole to pole.

“I’ve missed my stop!” he yelled at the driver. “Let me off here.”

“I can’t. I’m not allowed.”

“Chrissake, man. Just open the door at the junction. I’m not going to tell anybody. Up there, look, at the street corner.”

“I’m not allowed. I can’t let you off anywhere except at a proper stop. And you are not allowed to talk to me when I’m driving. Stand behind the line.”

“Stand behind the line, pajero! Stand behind the line? Don’t talk to you?” The tall man made a theatrical leap to the front of the bus. “See? I’m crossing the line and this is me talking to you. I’m talking to you right now. So what are you gonna do? You gonna put me off the bus?”

The driver hauled on the wheel as if he were at the helm of a three-master rounding the Horn and stood on the brakes so the whole bus sat down on its springs. The door opened with a wheeze and he said: “Off!”

The tall man flicked a finger and jumped into the street and the driver leaned out the window yelling after him. “Cabeza de mierda!” He sat down, growling, and looked in the mirror, right along the length of the bus, at Dr. Cochrane. “Sorry about that,” he said. “Sorry. Do you want off here?”

Dr. Cochrane folded his hands on top of his cane, rested his hands there and tipped his head forward, hiding behind his still-new hat. “I’m going right to the end,” he said.

“OK.” The driver pressed the lever to close the door and the bus started again with a jolt.

The argument with the tall man was annoying and unsettling. Bus journeys are supposed to be without incident. A bus driver is an automaton who turns the corner at the same place, changes gear at the same place, opens the door at the same place, brakes at the same place, along the same route at the same time over and over and over every day. He sees the same roads, the same buildings, the same traffic, the same people. There are no bus journeys, there is only one bus journey, indistinguishable from all the other bus journeys, so if a policemen were to come along and flash his badge and push his mirrored sunglasses a little further up his nose and stand on the step of the bus with his hip stuck out and his hand resting on his pistol and ask: “Have you seen this man?” the driver could only shrug and laugh at his own stupidity and hand the picture back and look at his feet. But not now. Not this time.

Dr. Cochrane kept looking down at the worn floor. There was a hatch there, some way for the mechanics at the depot to reach deep into the guts of the machine, outlined in an edge of aluminum with a hinged ring sunk flush into it. Dr. Cochrane examined it intently. He trailed his eye along every line, round every angle and every curve, running through equations and formulae in his head, choking down the bile that was rising in him as the bus lurched and swung.

“End of the line!” the driver shouted. The bus slowed, stopped with a high-pitched fart of brakes and a final, shuddering death rattle as the driver killed the engine. The door banged and he jumped down from the cab, stretching his arms over his head, groaning. Dr. Cochrane watched him walking with a slow, aching stride, patting his pockets for cigarettes and matches. When he reached the pallid cone of light falling from the street lamp, the damp stain of sweat down his spine stood out in an ugly stripe. The light cut him in half so his feet and his trousers shone and his face was hidden in shadow with just the burning dot of his cigarette to show where his mouth was.

Dr. Cochrane stood up and walked as quickly as he could to the front of the bus. He hooked his cane over his arm and swung himself from the dirty pole in the door, down two painful steps and on to the pavement. He hurried the length of the bus, keeping it between himself and the driver, and crossed the street into a narrow passage between two buildings.

He worked his way around, like a hunter moving through the woods when the wind was against him, leaning on his cane, tapping in the dark, discovering broken pavements and tin cans and broken bottles, straining his eyes in the lost light of uncurtained windows, the nebulous gray of unseen TVs that laughed at him as he passed. Slowly he was coming back the way he wanted to go, hidden by the houses, out of sight of the bus driver. He heard the engine start again, the bus shaking itself like an old dog, and he cursed. “I might just have waited,” he said. And he leaned a little more heavily on his cane until he was sure the bus had gone.

The street was silent. Dr. Cochrane limped between two bare and scrubby gardens, back to the bus stop, where he crossed the street and started the long climb up the hill in the dark. He was very afraid. He stopped often, because his leg hurt, because he was out of breath, and when he stopped he listened hard in case there was somebody climbing up the narrow path behind him. Nobody came. He heard dogs barking to each other in the night and the sound of a distant siren but nobody came. Dr. Cochrane stood in the darkness, straining his eyes. He concentrated on a gap in the trees where the lights of the houses shone through in a yellow glow, watching. If somebody was following up the path, no matter how quietly, they would pass there. He waited for their shadow. Still nobody came. After a little time he walked on up the hill until he came to a place where bindweed had knotted itself into the links of a broken chain fence and an old FC Atletico shirt had been draped over a post like a flag. With one last fearful look behind, Dr. Cochrane picked up the shirt, pushed through the gap and, holding his cane before him like a talisman, went down the hidden path on the other side.