`Here's tae King Billyl' A can was raised. 'God bless the Queen and King William of Orange!'

'Well said, son.’ The bowler hats said little, standing with the tips of their umbrellas touching the ground, hands resting lightly on the curved wooden handles. It was easy to dismiss these unsmiling men too lightly. But God help you if you started an argument with one of them.

'Why dae yis hate Catholics?’ a pedestrian yelled.

'We don't!' somebody yelled back, but she was already bustling away with her shopping bags. There were smiles, but she'd made her point. Rebus watched her go.

'Hey, Gavin, how long now?’

'Five minutes, just relax.’

Rebus looked towards the man who had just spoken, the man who was probably called Gavin MacMurray and therefore in charge. He seemed to have appeared from nowhere. Rebus had read the file on Gavin MacMurray: two arrests for breach of the peace and actual bodily harm, but a lot more information to his name than that. Rebus knew his age (38), that he was married and lived in Currie, and that he ran his own garage. He knew Inland Revenue had no complaints against him, that he drove a red Mercedes Benz (though he made his money. from more prosaic Fords, Renaults and the like), and that his teenage son had been in trouble for fighting, with two arrests after pitched battles outside Rangers matches and one arrest after an incident on the train home from Glasgow.

So Rebus assumed the teenager standing close beside Gavin MacMurray must be the son, Jamesie. Jamesie had pretensions of all obvious kinds. He wore sunglasses and a tough look, seeing himself as his father's lieutenant. His legs were -apart, shoulders back. Rebus had never seen anyone itching so badly for action of some kind. He had his father's low square jaw, the same black hair cut short at the front. But while Gavin MacMurray was dressed in chainstore anonymity, Jamesie wanted people to look at him. Biker boots, tight black jeans, white t-shirt and black leather jacket. He wore a red bandana around his right wrist, a studded leather strap around the left. His hair, long and curling at the back, had been shaved above both ears.

Turning from son to father was like turning from overt to covert strength. Rebus knew which he'd rather tackle. Gavin MacMurray was chewing gum with his front teeth, his head and eyes constantly in movement, checking things, keeping things in check. He kept his hands in his windcheater pockets, and wore silver-framed spectacles which magnified his eyes. There seemed little charisma about him, little of the rouser or orator. He looked chillingly ordinary.

Because he was ordinary, they all were, all these semi inebriated working men and retired men, quiet family types who might belong to the British Legion or their local Ex-Servicemen's Club, who might inhabit the bowling green on summer evenings and go with their families on holiday to Spain or Florida or Largs. It was only when you saw them in groups like this that you caught a whiff of something else. Alone, they had nothing but a nagging complaint; together, they had a voice: the sound of the lambeg, dense as a heartbeat; the insistent flutes; the march. They always fascinated Rebus. He couldn't help it. It was in his blood. He'd marched in his youth. He'd done a lot of things back then.

There was a final gathering of lines, MacMurray readying his troops. A word with the policeman in charge, a conversation by two-way radio, then a nod from MacMurray. The opening fat-fry of snare drums, the lambeg pumping away, and then the flutes. They marched on the spot for a few moments, then moved off towards Princes Street, where traffic had been stopped for them, where the Castle glared down on them, where a lot of people but by no means everyone paused to watch.

A few months back, a pro-republican march had been banned from this route. That was why the protesters were particularly loud in their jeers, thumbs held down. Some of them were chanting Na-Zis, Na-Zis, and then being told to shut up by uniformed police. There would be a few arrests, there always were. You hadn't had a good day out at a march unless there'd been at least the threat of arrest.

Rebus followed the march from the pavement, sticking to the Gardens side, which was quieter. A few more marchers had joined in, but it was still small beer, hardly worth the bother. He was beginning to wonder what he'd thought would happen. His eyes moved back through the procession from the tosser at the front, busy with his muckle stick, through the flutes and drums, past bowler hats and suits, to the younger marchers and stragglers. A few pre-teenage kids had joined in on the edges, loving every minute. Jamesie, right near the back, told them in no uncertain terms that they should leave, but they didn't listen to him. `Tough' always was a relative term.

But now one of the stragglers clutched Jamesie's arm and they shared a few words, both of them grinning. The straggler was wearing sunglasses with mirrored lenses, and a denim jacket with no shirt beneath.

`Hello,' said Rebus quietly. He watched Jamesie and Davey Soutar have their conversation, saw Jamesie pat Davey on the shoulder before Davey moved away again, falling back until he left the procession altogether, squeezing between two of the temporary barriers and vanishing into the crowd.

Jamesie seemed to relax a bit after this. His walk became looser, less of an act, and he swung his arms in time to the music. He seemed to be realising that it was a bright summer's day, and at last peeled off his leather jacket, slinging it over one shoulder, showing off his arm muscles and several tattoos. Rebus walked a bit faster, keeping close to the edge of the pavement. One of the tattoos was professional, and showed the ornately overlaid letters RFC: Rangers Football Club. But there was also the maroon emblem of Heart of Midlothian FC, so obviously Jamesie liked to play safe. Then there was a kilted, busby-wearing piper, and further down his arm towards the leather wristband a much more amateur job, the usual shaky greeny blue ink.

The letters SaS.

Rebus blinked. It was almost too far away for him to be sure. Almost. But he was sure. And suddenly he didn't want to talk to Gavin MacMurray any more. He wanted a word with his son.

He stopped on the pavement, letting the march pull away from him. He knew where they were heading. A left turn into Lothian Road, passing the windows of the Caledonian Hotel. Something for the rich tourists to get a picture of. Then another left into King"s Stables Road, stopping short of the Grassmarket. Afterwards, they'd probably head down into the Grassmarket itself for the post-march analysis and a few more beers. The Grassmarket being trendy these days, there'd be a lot of Fringe drinkers there too. A fine cocktail of cultures for a Saturday afternoon.

He followed the trail to one of the rougher pubs on the Cowgate, just the other side of Candlemaker Row from the Grassmarket. At one time, they'd hung miscreants from the gallows in the Grassmarket. It was a cheerier prospect these days, though you wouldn't necessarily know it from a visit to the Merchant's Bar where, at ten p.m. each night, the pint glasses were switched for flimsy plastic imposters, relieving the bar of ready weapons. It was that kind of place.

Inside, the bar was airless, a drinkers' fug of smoke and television heat. You didn't come here for a good time, you came out of necessity. The regulars were like dragons, each mouthful cooling the fire inside them. As he entered the bar, he saw no one he recognised, not even the barman. The barman was a new face, just out of his teens. He poured pints with an affected disdain, and took the money like it was a bribe. From the sounds of atonal song, Rebus knew the marchers were upstairs, probably emptying the place.

Rebus took his pint – still in a glass glass – and headed up to the dance hall. Sure enough, the marchers were about all there was. They'd shed jackets, ties, and inhibitions, and were milling around, singing to off -key flutes and downing pints and shorts. Getting the drink in had become a logistical nightmare, and more marchers were coming in all the time.