It was almost two before there was a chance for lunch. Until then his desk was snow-banked with demanding papers, his telephone rang constantly and an army of insistent visitors attacked his walls. By twelve, his nerves were pulled like violin strings knobbed to their tightest. By one, the strings drew close to shearing; by one-thirty they began to snap. He had to get away; now, immediately; flee to some shadowy restaurant booth, have a cocktail and a leisurely meal; listen to somnolent music. He had to.

Down on the street, he walked beyond the zone of eating places he usually frequented, not wishing to risk seeing anyone he knew. About a quarter of a mile from the office he found a cellar restaurant named Franco's. At his request, the hostess led him to a rear booth where he ordered a martini; then, as the woman turned away, he stretched out his legs beneath the table and closed his eyes. A grateful sigh murmured from him. This was the ticket. Dim-lit comfort. Muzak thrumming at the bottom fringe of audibility, a curative drink. He signed again. A few more days like this, he thought, and I'm gone.

'Hi, Don.'

He opened his eyes in time to see the man drop down across from him, 'How goes it?' asked the man.

'What?' Donald Marshall stared at him.

'Gawd,' said the man. 'What a day, what a day.' He grinned tiredly. 'You, too?'

'I don't believe -' began Marshall.

'Ah!' the man said, nodding, pleased, as a waitress brought the martini. 'That for me. Another, please; dryer than dry.'

'Yes, sir,' said the waitress and was gone.

'There,' said the man, stretching. 'No place like Franco's for getting away from it all, eh?'

'Look here,' said Marshall, smiling awkwardly. 'I'm afraid you've made a mistake.'

'Hmmm?' The man leaned forward, smiling back.

T say I'm afraid you've made a mistake.'

'I have?' The man grunted. 'What'd I do, forget to shave? I'm liable to. No?' he said as Marshall frowned. 'Wrong tie?'

'You don't understand,' said Marshall.

What?'

Marshall cleared his throat. 'I'm �C not who you think I am,' he said.

'Huh?' The man leaned forward again, squinting. He straightened up, chuckling. 'What's the story, Don?' he asked.

Marshall fingered at the stem of his glass. 'Yes, what is the story?' he said, less politely now.

'I don't get you,' said the man.

'Who do you think I am?' asked Marshall, his voice rising a little.

The man began to speak, gaped a trifle, then began to speak again. 'What do you mean who do I -?' He broke off as the waitress brought the second martini. They both sat quietly until she was gone.

'Now,' said the man curiously.

'Look, I'm not going to accuse you of anything,' said Marshall, 'but you don't know me. You've never met me in your whole life.'

'I don't -!' The man couldn't finish; he looked flabbergasted. 'I don't know you?' he said.

Marshall had to laugh. 'Oh this is ludicrous,' he said.

The man smiled appreciatively. 'I knew you were ribbing me,' he admitted, 'but �C ' He shook his head. 'You had me going there for a second.'

Marshall put down his glass, the skin beginning to tighten across his cheeks.

Td say this had gone about far enough,' he said. 'I'm in no mood for -'

'Don,' the man broke in. 'What's wrong?'

Marshall drew in a deep breath, then let it waver out. 'Oh, well,' he said, 'I suppose it's an honest mistake.' He forced a smile. 'Who do you think I am?'

The man didn't answer. He looked at Marshall intently.

'Well?' asked Marshall, beginning to lose patience.

'This isn't a joke?' said the man,

'Now, look -'

'No, wait, wait,' the man said, raising one hand. 'I... suppose it's possible there could be two men who look so much alike they -'

He stopped abruptly and looked at Marshall. 'Don, you're not ribbing me, are you?'

'Now listen to me -!'

'All right, I apologise,' said the man. He sat gazing at Marshall for a moment; then he shrugged and smiled perplexedly. 'I could have sworn you were Don Marshall,' he said.

Marshall felt something cold gathering around his heart.

'I am,' he heard himself say.

The only sound in the restaurant was that of the music and the delicate clink of silverware.

'What is this?' asked the man.

'You tell me,' said Marshall in a thin voice.

'You �C ' The man looked carefully at him. 'This is not a joke,' he said.

'Now see here!'

'All right, all right, The man raised both his hands in a conciliatory gesture. 'It's not a joke. You claim I don't know you. All right. Granting that leaves us with �C with this: a man who not only looks exactly like my friend but has exactly the same name. Is this possible?'

'Apparently so,' said Marshall.

Abruptly, he picked up his glass and took momentary escape in the martini. The man did the same. The waitress came for their orders and Marshall told her to come back later.

' What's your name?' he asked then.

'Arthur Nolan,' said the man.

Marshall gestured conclusively. 'I don't know you,' he said. There was a slight loosening of tension in his stomach.

The man leaned back and stared at Marshall. This is fantastic,' he said. He shook his head. 'Utterly fantastic'

Marshall smiled and lowered his eyes to the glass.

'Where do you work?' asked the man.

'American-Pacific Steamship,' Marshall answered, glancing up. He felt the beginning of enjoyment in himself. This was, certainly, something to take one's mind off the wrack of the day.

The man looked examiningly at him; and Marshall sensed the enjoyment fading.

Suddenly the man laughed.

'You must have had one sweet hell of a morning, buddy,' he said.

'What?'

'No more,' said the man.

'Listen -'

'I capitulate,' said Nolan, grinning. 'You're curdling my gin.'

'Listen to me, damn it!' snapped Marshall.

The man looked startled. His mouth fell open and he put his drink down. 'Don, what is it?' he asked, concerned now.

'You do not know me,' said Marshall, very carefully. 'I do not know you. Will you kindly accept that?'

The man looked around as if for help. Then he leaned in close and spoke, his voice soft and worried.

'Don, listen. Honestly. You don't know me?'

Marshall drew in a deep breath, teeth clenched against rising fury. The man drew back. The look on his face was, suddenly, frightening to Marshall.

'One of us is out of his mind,' Marshall said. The levity he'd intended never appeared in his voice.

Nolan swallowed raggedly. He looked down at his drink as if unable to face the other man.

Marshall suddenly laughed. 'Dear Lord,' he said, 'What a scene. You really think you know me, don't you?'

The man grimaced. The Don Marshall I know,' he said, 'also works for American-Pacific.'

Marshall shuddered. That's impossible,' he said.

'No,' said the man flatly.

For a moment Marshall got the notion that this was some sort of insidious plot against him; but the distraught expression on the man's face weakened the suspicion. He took a sip of his martini, then, carefully, set down the glass and laid his palms on the table as if seeking the reinforcement of its presence.

'American-Pacific Steamship Lines?' he asked.

The man nodded once. 'Yes.'

Marshall shook his head obdurately; 'No,' he said. 'There's no other Marshall in our offices. Unless,' he added, quickly, 'one of our clerks downstairs -'

'You're an- ' The man broke off nervously. 'He's an executive,' he said.

Marshall drew his hands in slowly and put them in his lap. Then I don't understand,' he said. He wished, instantly, he hadn't said it.

This... man told you he worked there?' he asked quickly.

'Yes.'

'Can you prove he works there?' Marshall challenged, his voice breaking, 'Can you prove his name is really Don Marshall?'

'Don, I -'

'Well, can you?'

'Are you married?' asked the man.

Marshall hesitated. Then, clearing his throat, he said, 'I am.'

Nolan leaned forward. To Ruth Foster?' he asked.

Marshall couldn't hide his involuntary gasp.

'Do you live on the Island?' Nolan pressed.

'Yes,' said Marshall weakly, 'but -'

'In Huntington?'

Marshall hadn't even the strength to nod.

'Did you go to Columbia University?'

'Yes, but -' His teeth were on edge now.

'Did you graduate in June, nineteen forty?'

'No!' Marshall clutched at this. 'I graduated in January, nineteen forty-one. Forty-one!'

'Were you a lieutenant in the Army?' asked Nolan, paying no attention.

Marshall felt himself slipping. 'Yes,' he muttered, 'but you said -'

'In the Eighty-Seventh Division?'

'Now wait a minute!' Marshall pushed aside the nearly empty glass as if to make room for his rebuttal. 'I can give you two very good explanations for this... this fool confusion.

One: a man who looks like me and knows a few things about me is pretending to be me; Lord knows why.

Two: you know about me and you're trying to snare me into something. No, you can argue all you like!' he persisted, almost frantically, as the man began to object. 'You can ask all the questions you like; but I know who I am and I know who I know!'

'Do you?' asked the man. He looked dazed.

Marshall felt his legs twitch sharply.

'Well, I have no intention of s-sitting here and arguing with you,' he said. 'This entire thing is absurd. I came here for some peace and quiet �C a place I've never even been to before and -'

'Don, we eat here all the time.' Nolan looked sick.

That's nonsense!'

Nolan rubbed a hand across his mouth. 'You... you actually think this is some kind of con game?' he asked.

Marshall stared at him. He could feel the heavy pulsing of his heart.

'Or that �C my God - that there's a man impersonating you? Don...' The man lowered his eyes. T think �C well, if I were you/ he said quietly, 'I'd �C go to a doctor, a -'

'Let's stop this, shall we?' Marshall interrupted coldly. 'I suggest one of us leave.' He looked around the restaurant. 'There's plenty of room in here.'

He turned his eyes quickly from the man's stricken face and picked up his martini. 'Well?' he said.

The man shook his head. 'Dear God,' he murmured.

'I said let's stop it,' Marshall said through clenched teeth.

'That's it?' asked Nolan, incredulously. 'You're willing to -to let it go at that?'

Marshall started to get up.

'No, no, wait,' said Nolan. TU go.' He stared at Marshall blankly. 'I'll go,' he repeated.

Abruptly, he pushed to his feet as if there were a leaden mantle around his shoulders.

'I don't know what to say,' he said, 'but �C for God's sake, Don �C see a doctor.'

He stood by the side of the booth a moment longer, looking down at Marshall. Then, hastily, he turned and walked towards the front door. Marshall watched him leave.

When the man had gone he sank back against the booth wall and stared into his drink. He picked up the toothpick and mechanically stirred the impaled onion around in the glass. When the waitress came he ordered the first item he saw on the menu.

While he ate he thought about how insane it had been. For, unless the man Nolan was a consummate actor, he had been sincerely upset by what had happened.

What had happened? An out-and-out case of mistaken identity was one thing. A mistaken identity which seemed not quite wholly mistaken was another. How had the man known these things about him? About Ruth, Huntington, American-Pacific, even his lieutenancy in the 87th Division? How?

Suddenly, it struck him.

Years ago he'd been a devotee of fantastic fiction �C stories which dealt with trips to the moon, with travelling through time, with all of that. And one of the ideas used repeatedly was that of the alternate universe: a lunatic theory which stated that for every possibility there was a separate universe. Following his theory there might, conceivably, be a universe in which he knew this Nolan, ate at Franco's with him regularly and had graduated from Columbia a semester earlier.

It was absurd, really, yet there it was. What if, in entering Franco's, he had, accidentally, entered a universe one jot removed from the one he'd existed in at the office? What if, the thought expanded, people were, without knowing it, continually entering these universes one jot removed? What if he himself had continually entered them and never known until today �C when, in an accidental entry, he had gone one step too far?

He closed his eyes and shuddered. Dear Lord, he thought; dear, heavenly Lord, I have been working too hard. He felt as if he were standing at the edge of a cliff waiting for someone to push him off. He tried hard not to think about his talk with Nolan. If he thought about it he'd have to fit into the pattern. He wasn't prepared to do that yet.

After a while he paid his check and left the restaurant, the food like cold lead in his stomach. He cabbed to Pennsylvania Station and, after a short wait, boarded a North Shore train. All the way to Huntington, he sat in the smoker car staring out at the passing countryside, an unlit cigarette between his fingers. The heavy pressure in his stomach wouldn't go away.

When Huntington was reached, he walked across the station to the cab stand and, deliberately, got into one of them.

Take me home, will you?' he looked intently at the driver.

'Sure thing, Mr Marshall,' said the driver, smiling.

Marshall sank back with a wavering sigh and closed his eyes. There was a tingling at his fingertips.

'You're home early,' said the driver. 'Feeling poorly?'

Marshall swallowed. 'Just a headache,' he said.

'Oh, I'm sorry.'

As he rode home, Marshall kept staring at the town, despite himself, looking for discrepancies, for differences. But there were none; everything was just the same. He felt the pressure letting up.

Ruth was in the living room, sewing.

'Don.' She stood up and hurried to him. 'Is something wrong?'

'No, no,' he said putting down his hat. 'Just a headache.'

'Oh.' She led him, sympathetically, to a chair and helped him off with his suit coat and shoes. 'I'll get you something right away,' she said.

'Fine.' When she was gone upstairs, Marshall looked around the familiar room and smiled at it. It was all right now.

Ruth was coming down the stairs when the telephone rang. He started up, then fell back again as she called, 'I'll get it, darling.'

'All right,' he said.

He watched her in the hallway as she picked up the receiver and said hello. She listened. 'Yes, darling,' she said automatically. 'You -'

Then she stopped and, holding out the receiver, stared at it as if it were something monstrous in her hand.

She put it back-to her ear. 'You... won't be home until late?' she asked in a faint voice.

Marshall sat there gaping at her, the beats of his heart like someone striking at him. Even when she turned to look at him, the receiver lowered in her hand, he couldn't turn away. Please, he thought. Please don't say it. Please.

'Who are you?' she asked.