Eusden woke with a start. Dawn had broken, grey and grudging. Its dusty light revealed the anonymous furnishings of a room he did not immediately recognize. For a moment, he could not even have said where he was. Then the events of the previous day avalanched back into his mind. And the prevailing silence expanded ominously.

He threw on his clothes, calling Marty’s name as he did so. But the call went unanswered. The flat was small. It took only a few seconds to confirm he was alone.

Then he noticed the envelope full of money still lying on the coffee table in the lounge. If Marty had taken any of it, he had certainly not taken much. Was that, Eusden wondered, his idea of an honourable parting? A debt settled. But a secret kept. He could only repeat what he had said when his friend had jumped bail, forfeiting his surety. ‘Fuck you, Marty.’

‘Nice greeting,’ said Marty, coming through the front door just as Eusden spoke. ‘A simple “Good morning” would have sufficed.’ He was wearing a parka and carrying a travel bag. Though pale, gaunt and unshaven, he looked absurdly cheerful and was munching a pretzel. ‘You didn’t think I’d run out on you, did you?’

‘It wouldn’t be the first time,’ Eusden responded defensively.

‘What it is to have a reputation.’ Marty hung up his coat and strolled into the lounge.

‘Where’ve you been?’

‘The hotel I was supposed to check out of yesterday morning. Werner had paid my bill, considerate fellow that he is, and had them pack my stuff to await collection. So why don’t you make coffee while I put some of my own clothes on? After breakfast you can take second turns with my toothbrush and shaver. Can I say fairer than that?’

A mug of black coffee was ready and waiting for Marty when he entered the kitchen five minutes later, in clean sweatshirt and jeans and eagerly peeling the cellophane off a pack of Camel cigarettes. ‘Don’t look at me like that,’ he said, catching Eusden’s wince. ‘I’m not going to die of lung cancer, am I?’ He lit up, sat down at the formica-topped table and took a sip of coffee. ‘Why can’t I smell bacon frying?’

‘Because there’s none to fry. The menu’s cornflakes – without milk.’

‘OK. We’ll breakfast out. Meanwhile-’

‘Meanwhile you’ve got some talking to do.’ Eusden sat down at the other end of the table, theatrically fanning away the cigarette smoke as he blew on his coffee.

‘Does that mean you’re in?’

‘I guess so.’

‘I’m looking for something more definite than that, Richard.’

‘What did you have in mind?’

‘Phone the office and say you’re taking the rest of the week off. Personal emergency. Compassionate leave. Your budgie’s died. Whatever. Tell the FO to FO.’

‘There won’t be anybody in yet. They’re an hour behind, remember.’

‘Leave a recorded message. All the better. No need to explain.’

‘I’ll have to explain eventually.’ Somewhere deep in Eusden’s brain, a series of calculations was under way. He had to find out what Clem Hewitson’s secret was. He knew himself well enough to understand that he would regret failing to do so for a long time, possibly for ever. Too much of his own past was tied to his memory of the old man for him simply to walk away. He was also aware that part of him had been excited by the intrigue and uncertainty of the previous twenty-four hours. He had felt more alive during them than he had in months – if not years. Creeping back timidly to his desk in Whitehall was in truth not even an option. ‘OK. I’ll make the call.’ He rose and headed for the spare bedroom. ‘My phone’s in my bag.’

‘No.’ Marty grabbed his arm as he passed. ‘Use the land line.’

‘What?’

‘I’m serious. Turn your mobile off and leave it that way. We need to be untraceable from now on.’

Eusden looked at his friend disbelievingly. ‘Come off it, Marty. It can’t be-’

‘But it is.’

‘This had better be good.’

‘Or bad. Oh, yes. It is. One of those. Or both. You can be the judge.’

‘Lorraine, this is Richard. More apologies for you to make on my behalf, I’m afraid. I’m dealing with a… family crisis. I’m going to be away until the end of the week. I have unused leave, so it should be no problem. I’ll call you when the situation’s clearer. ’Bye.’ Eusden put the phone down and returned to the kitchen. ‘It’s done,’ he announced.

‘Unused leave? That sounds sad.’

‘Can we get on with it?’

‘Actually, no. This flat gives me the creeps. I’ve spent far too long staring at its puce-coloured walls. Why don’t we pack up and clear out? There’s a café round the corner that was just opening when I went past in the taxi. We can get some breakfast there and much better coffee than this stuff you scraped out of a jar.’

‘When are you going to stop stringing me along, Marty?’

‘When I’ve lit my first postprandial cigarette. Which, if you shift yourself, won’t be long.’

Eusden washed and shaved in short order. When it came down to it, he had no more wish to linger in the flat than Marty. They made no effort to clear up after themselves. (‘That’s Werner’s problem,’ declared Marty. ‘He’s got a week or more before Mutter gets back from Majorca.’) They slammed the door behind them and strode away without a backward glance, studiously avoiding eye contact with a neighbour walking her dog.

There was a broad, paved square a few minutes away. The Café Sizilien stood in one corner. Assorted Hamburgers bound for work were bracing themselves for the experience with coffee and croissants and certainly the morning was cold enough to warrant a good deal of bracing. Marty opted for two boiled eggs and several thickly jammed and buttered bread rolls. Eusden joined him, surprised by how hungry he felt. The coffee, as Marty had promised, was a vast improvement on Frau Straub’s instant.

‘No sign of Werner’s heavy,’ said Marty, scanning the customers from their window table as he licked raspberry jam off his fingers. ‘He’s betting I’ll take the money and run.’

‘Instead of which… you’re just taking the money.’

‘You’ll get your share.’

‘That’s not what I meant.’

‘No, I guess not. Sorry.’ Marty lit his second Camel of the day. ‘So, where to begin?’

‘How about the beginning?’

‘Easier said than done. But I’ll try.’ Marty pulled out his wallet and fished something small and flimsy from its depths. He laid it in front of Eusden. ‘What do you make of that?’

It was a fragment of an envelope with two stamps stuck to it. The smaller had a king’s head on it beneath the word DANMARK. The larger depicted a ploughman struggling to control his horse as a plane flew overhead. Beneath the ploughman appeared the words DANMARK LUFTPOST. A single postmark covered both: KØBENHAVN LUFTPOST 17.5.27.

‘What am I supposed to make of it?’ Eusden queried.

‘Danish, right?’

‘Obviously.’

‘Twenty-five øre King Christian the Tenth with twenty-five øre airmail supplement. Part of my dad’s collection. I never actually looked through it until he died. I mean, philately? Do me a favour. But ask yourself: where’d he get it from?’

‘No idea.’

‘Yes, you have. Who would a stamp-mad schoolboy cadge something like that off?’

‘His father?’

‘Exactly. Clem.’

‘So, Clem had a letter from Denmark.’

‘Yes. Which he must have hung on to, since Dad was only six years old in 1927. He didn’t get into stamp collecting until his early teens.’

‘OK. But-’

‘Did you know Clem spoke Danish?’

‘What?’

‘Well, spoke might be an exaggeration. But he certainly read it.’

‘You’re having me on.’

‘No. You asked me what’s in the attaché case. The answer is a collection of letters, written to Clem over a period of ten years or more in the nineteen twenties and thirties. In Danish. Now you can see why I couldn’t make head or tail of the contents of the case.’