She felt impotent – and yet overwhelmed with her potential power; she experienced both sensations at once, finding the mixture radically unpleasant. Bring some artifact back to the present for Wash-35? Or check on some research quibble, settle some historical dispute? Snare the actual authentic Babe Ruth, bring him back to inhabit our Martian enterprise? It would certainly impart verisimilitude.

'Virgil Ackerman,' she said slowly, 'is alive in this period as a small boy. Does that suggest anything?'

'No,' the cab said.

'It gives me enormous power over him.' She opened her purse. 'I'll give him something. The coins I have, bills.' Whisper to him the date the United States enters the war, she thought. He can use that knowledge later on, somehow ... he'll find a way; he's always been smart, much smarter than I. God, she thought, if only I could put my finger on it! Tell him to invest in what? General Dynamics? Bet on Joe Louis in every fight? Buy real estate in Los Angeles? What do you tell an eight- or nine-year-old boy when you have exact and complete knowledge of the next hundred and twenty years?

'Miss,' the cab said plaintively, 'we've been in the air so long that I'm running short of fuel.'

Chilled, she said, 'But you ought to be good for fifteen hours.'

'I was low.' It admitted this reluctantly. 'It's my fault; I'm sorry. I was on my way to a service station when you contacted me.'

'You damn fool mechanism,' she said with fury. But that was that; they couldn't reach Washington D.C.; they were at least a thousand miles from it. And this period, of course, lacked the high-grade super-refined protonex which the cab required. And then all at once she knew what she had to do. The cab had given her the idea, unintentionally. Protonex was the finest fuel ever developed – and it was derived from sea water. All she had to do was mail a container of protonex to Virgil Ackerman's father, instruct him to procure analysis of it and then a patent on it.

But there was no way she could mail anything, not without money to buy stamps. In her purse she had a small wad of dogeared postage stamps, but of course all from her own era, from 2055. ——, she said furiously to herself, overwhelmed. Here I have it right before me, the solution as to what I should do – and I can't do it.

'How,' she asked the cab, 'can I send a letter in this time period with no contemporary stamps? Tell me that.'

'Send the letter unstamped, with no return address, miss. The post office will deliver it with a postage due stamp attached.'

'Yes,' she said, 'of course.' But she could not get protonex into a first-class envelope; it would have to go parcel post, and in that class, lacking franking power, it would not be delivered. 'Listen,' she said. 'Do you have any transistors in your circuits?'

'A few. But transistors became obsolete when—'

'Give me one. I don't care what it does to you; yank it out and let me have it, and the smaller it is the better.'

Presently, from the slot in the back of the seat before her, a transistor rolled; she caught it as it fell.

That puts my radio transmitter out of service,' the cab complained. 'I'll have to bill you for it; it'll be expensive because of—'

'Shut up,' Kathy said. 'And land in that town; get down as soon as you can.' She wrote hurriedly on the tablet of paper: 'This is a radio part from the future, Virgil Ackerman. Show it to no one but save it until the early 1940s. Then take it to Westinghouse Corp. or to General Electric or any electronics (radio) firm. It will make you rich. I am Katherine Sweetscent. Remember me for this, later on.'

The cab landed gingerly on the roof of an office building in the centre of the small town. Below on the sidewalk the rustic, archaic-looking passers-by gaped.

'Land on the street,' Kathy reinstructed the cab. 'I have to put this in the mail.' She found an envelope in her purse, hurriedly wrote out Virgil's address in Wash-35, put the transistor and note into the envelope and sealed it. Below them the street with its obsolete old cars rose slowly.

A moment later she was racing to a mailbox; she deposited the letter and then stood gasping for breath.

She had done it. Insured Virgil's economic future and therefore her own. This would make his career and hers forever.

The hell with you, Eric Sweetscent, she said to herself. I don't ever have to marry you now; I've left you behind.

And then she realized with dismay, I've still got to marry you in order to acquire the name. So that Virgil can identify me, later on in the future, in our own time. What she had done, then, came to exactly nothing.

Slowly, she returned to the parked cab.

'Miss,' the cab said, 'can you help me find fuel, please?'

'You won't find any fuel here,' Kathy said. Its obstinate refusal – or inability – to grasp the situation maddened her. 'Unless you can run on sixty octane gasoline, which I very much doubt.'

A passer-by, a middle-aged man wearing a straw hat, frozen in his tracks by the sight of the autonomic cab, called to her, 'Hey lady, what's that, anyhow? A US Marine Corps secret weapon for war games?'

'Yes,' Kathy answered. 'And in addition later on it'll stop the Nazis.' As she boarded the cab she said to the group of people who had cautiously formed around the cab at a safe distance, 'Keep the date December 7, 1941, in mind; it'll be a day to remember.' She closed the cab door. 'Let's go. I could tell those people so much ... but it seems hardly worth it. A bunch of Middle Western hicks.' This town, she decided, lay either in Kansas or Missouri, from the looks of it. Frankly, it repelled her.

The cab dutifully ascended.

The 'Starmen should see Kansas in 1935, she said to herself. If they did they might not care to take over Terra; it might not seem worth it.

To the cab she said, 'Land in a pasture. We'll sit it out until we're back in our own time period.' It probably would not be long, now; she had an impression of a devouring insubstanti-ality here in this era – the reality outside the cab had gained a gaseous quality which she recognized from her previous encounter with the drug.

'Are you joking?' the cab said. 'Is it actually possible that we—'

'The problem,' she said tartly, 'is not in returning to our own time; the problem is finding a way to stay under the drug's influence until something of worth can be accomplished.' The time was just not long enough.

'What drug, miss?'

'None of your goddam business,' Kathy said. 'You nosy autonomic nonentity with your big prying circuits all opened up and flapping.' She lit a cigarette and leaned back against the seat, feeling weary. It had been a tough day and she knew, with acuity, that more lay ahead.

The sallow-faced young man, who oddly enough already possessed a conspicuous paunch, as if physically yielding to the more lush pleasures at this, the planet's financial and political capital, shook Eric Sweetscent's hand damply and said, 'I'm Don Festenburg, doctor. It's good to hear you're joining us. How about an old-fashioned?'

'No thanks,' Eric said. There was something about Festenburg which he did not care for, but he could not put his finger on it. Despite his obesity and bad complexion Festenburg seemed friendly enough, and certainly he was competent; the latter alone counted, after all. But – Eric pondered as he watched Festenburg mix himself his drink. Perhaps it's because I don't think anyone should speak for the Secretary, he decided. I'd resent anyone who holds the job Festenburg does.

'Since we're alone,' Festenburg said, glancing around the room, 'I'd like to suggest something that may make me more, palatable to you.' He grinned knowingly. 'I can tell what your feelings are; I'm sensitive, doctor, even if I'm the pyknic body-type. Suppose I suggested that an elaborate ruse has been carried off successfully, convincing even you. The flabby, aging, utterly discouraged and hypochondriacal Gino Molinari whom you've met and accepted as the authentic UN Secretary—' Festenburg lazily stirred his drink, eyeing Eric. 'That's the robant simulacrum. And the robust, energetic figure you witnessed on video tape a short while ago is the living man. And this ruse must necessarily be maintained, of course, to sidetrack no one else but our beloved ally, the 'Starmen.'