Use of English PRO

We live on the island of Hale. It's about four kilometres long and two kilometres wide at its broadest point, and it's joined to the mainland by a causeway called the Stand - a narrow road built across the mouth of the river which separates us from the rest of the country. Most of the time you wouldn't know we're on an island because the river mouth between us and the mainland is just a vast stretch of tall grasses and brown mud. But when there's a high tide and the water rises a half a metre or so above the road and nothing can pass until the tide goes out again a few hours later, then you know it's an island.
We were on our way back from the mainland. My older brother, Dominic, had just finished his first year at university in a town 150 km away. Dominic's train was due in at five and he'd asked for a lift back from the station. Now, Dad normally hates being disturbed when he's writing (which is just about all the time), and he also hates having to go anywhere, but despite the typical sighs and moans - why can't he get a taxi? what's wrong with the bus? - I could tell by the sparkle in his eyes that he was really looking forward to seeing Dominic.
So, anyway, Dad and I had driven to the mainland and picked up Dominic from the station. He had been talking non-stop from the moment he'd slung his rucksack in the boot and got in the car. University this, university that, writers, books, parties, people, money, gigs…. And when I say talking, I don't mean talking as in having a conversation, I mean talking as in jabbering like a mad thing. I didn't like it ... the way he spoke and waved his hands around as if he was some kind of intellectual or something. It was embarrassing. It made me feel uncomfortable - that kind of discomfort you feel when someone you like, someone close to you, suddenly starts acting like a complete idiot. And I didn't like the way he was ignoring me, either. For all the attention I was getting I might as well not have been there. I felt a stranger in my own car.
As we approached the island on that Friday afternoon, the tide was low and the Stand welcomed us home, stretched out before us, clear and dry, beautifully hazy in the heat - a raised strip of grey concrete bound by white railings and a low footpath on either side, with rough cobbled banks leading down to the water. Beyond the railings, the water was glinting with that wonderful silver light we sometimes get here in the late afternoon which lazes through to the early evening.
We were about halfway across when I saw the boy. My first thought was how odd it was to see someone walking on the Stand. You don't often see people walking around here. Between Hale and Moulton (the nearest town about thirty kilometres away on the mainland), there's nothing but small cottages, farmland, heathland and a couple of hills. So islanders don't walk because of that. If they're going to Moulton they tend to take the bus. So the only pedestrians you're likely to see around here are walkers or bird-watchers. But even from a distance I could tell that the figure ahead didn't fit into either of these categories. I wasn't sure how I knew, I just did.
As we drew closer, he became clearer. He was actually a young man rather than a boy. Although he was on the small side, he wasn't as slight as I'd first thought. He wasn't exactly muscular, but he wasn't weedy-looking either. It's hard to explain. There was a sense of strength about him, a graceful strength that showed in his balance, the way he held himself, the way he walked!