"One of my guests?"

"Oh, shut it, Sharpie; you are never interested in the morals of your guests. If they can be depended on to throw custard pies or do impromptu strips or some other prank that will keep your party from growing dull, that qualifies them. However, I am not assuming that the boss villain was at your party; I am saying that he would not be lurking where the Man might put the arm on him. Your house would be the best place to hide and watch the plot develop.

"But, guest or not, he was someone who knew that Doctor Burroughs would be at your party. Hilda, who knew that key fact?"

She answered with uncustomary seriousness. "I don't know, Zebbie. I would have to think."

"Think hard."

"Mmm, not many. Several were invited because Jake was coming-you, for example-"

"I became aware of that."

"-but you weren't told that Jake would be present. Some were told-'No Brain,' for example-but I can't imagine that old fool booby-trapping a car."

"I can't either, but killers don't look like killers; they look like people. How long before the party did you tell 'Brainy' that Pop would be present?"

"I told him when I invited him. Mmm, eight days ago."

I sighed. "The possibles include not only the campus but the entire globe. So we must try to figure probables. Doctor Burroughs, can you think of anyone who would like to see you dead?"

"Several !"

"Let me rephrase it. Who hates your guts so bitterly that he would not hesitate to kill your daughter as long as he got you? And also bystanders such as Hilda and me. Not that we figure, save to show that he didn't give a hoot who caught it. A deficient personality. Amoral. Who is he?"

Pop Burroughs hesitated. "Doctor Carter, disagreement between mathematicians can be extremely heated... and I am not without fault." (You're telling me, Pop!) "But these quarrels rarely result in violence. Even the death of Archimedes was only indirectly related to his-our-profession. To encompass my daughter as well-no, even Doctor Brain, much as I despise him, does not fit the picture."

Deety said, "Zeb, could it have been me they were shooting at?"

"You tell me. Whose dolly have you busted?"

"Hmm- I can't think of anyone who dislikes me even enough to snub me. Sounds silly but it's true."

"It's the truth," put in Sharpie. "Deety is just like her mother was. When

Jane-Deety's mother, and my best friend until we lost her-when Jane and

I were roommates in college, I was always getting into jams and Jane was

always getting me out-and never got into one herself. A peacemaker. So is

Deety."

"Okay, Deety, you're out of it. So is Hilda and so am I, as whoever placed that booby trap could not predict that either Hilda or I would be in blast range. So it's Pop they're gunning for. Who we don't know, why we don't know. When we figure out why, we'll know who. Meantime we've got to keep Pop out of range. I'm going to marry you as fast as possible, not only because you smell good but to give me a legitimate interest in this fight."

"So we go first to Reno."

"Shut up, Sharpie. We've been on course for Reno since we leveled off." I flipped on the transponder, but to the left, not right. It would now answer with a registered, legal signal... but not one registered to my name. This cost me some shekels I did not need but were appreciated by a tight-lipped family man in Indio. Sometimes it is convenient not to be identified by sky cops every time one crosses a state line.

"But we aren't going to Reno. Those cowboy maneuvers were intended to deceive the eye, radar, and heat seekers. The evasion against the heat seekers-that rough turn while we were still in glide-either worked or was not needed, as we haven't had a missile up the tail. Probably wasn't needed; people who booby-trap cars aren't likely to be prepared to shoot a duo out of the sky. But I couldn't be certain, so I ducked. We may be assumed to be dead in the blast and fire, and that assumption may stand up until the mess has cooled down and there is daylight to work by. Even later it may stand up, as the cops may not tell anyone that they were unable to find organic remains. But I must assume that Professor Moriarty isn't fooled, that he is watching by repeater scope in his secret HQ, that he knows we are headed for Reno, and that hostiles will greet us there. So we won't go there. Now quiet, please; I must tell this baby what to do."

The computer-pilot of my car can't cook but what she can do, she does well. I called for display map, changed scale to include Utah, used the light pen to trace route-complex as it curved around Reno to the south, back north again, made easting over some very empty country, and passed north of Hill Air Force Range in approaching Logan. I fed in height-above-ground while giving her leeway to smooth out bumps, and added one change in speed-over-ground once we were clear of Reno radar. "Got it, girl?" I asked her.

"Got it, Zeb."

"Ten-minute call, please."

"Call you ten minutes before end of routing-right!"

"You're a smart girl, Gay."

"Boss, I bet you tell that to all the girls. Over."

"Roger and out, Gay." The display faded.

Certainly I could have programmed my autopilot to accept a plan in response to a punched "Execute." But isn't it pleasanter to be answered by a warm contralto? But the "smart girl" aspect lay in the fact that it took my voice to make a flight plan operative. A skilled electron pusher might find a way to override my lock, then drive her manually. But the first time he attempted to use autopilot, the car would not only not accept the program but would scream for help on all police frequencies. This causes car thieves to feel maladjusted.

I looked up and saw that Deety had been following this intently. I waited for some question. Instead Deety said, "She has a very pleasant voice, Zeb."

"Gay Deceiver is a very nice girl, Deety."

"And talented. Zeb, I have never before been in a Ford that can do the things this car-Gay Deceiver?-can do."

"After we're married I'll introduce you to her more formally. It will require reprogramming."

"I look forward to knowing her better."

"You will. Gay is not exactly all Ford. Her external appearance was made by Ford of Canada. Most of the rest of her once belonged to Australian Defense Forces. But I added a few doodads. The bowling alley. The powder room. The veranda. Little homey touches."

"I'm sure she appreciates them, Zeb. I know I do. I suspect that, had she not had them, we would all be as dead as canasta."

"You may be right. If so, it would not be the first time Gay has kept me alive. You have not seen all her talents."

"I'm beyond being surprised. So far as I could see you didn't tell her to land at Logan."

"Logan seems to be the next most likely place for a reception committee. Who in Logan knows that you and your father were going to visit Hilda?"

"No one, through me."

"Mail? Milk cartons? Newspapers?"

"No deliveries to the house, Zeb." She turned her head, "Pop, does anyone in Logan know where we went?"

"Doctor Carter, to the best of my knowledge, no one in Logan knows that we left. Having lived many years in the buzzing gossip of Academe, I have learned to keep my life as private as possible."

"Then I suggest that you all ease your belts and sleep. Until ten minutes before reaching Logan there is little to do."

"Doctor Carter-"

"Better call me Zeb, Pop. Get used to it."

"Zeb' it is, son. On page eighty-seven of your monograph, after the equation numbered one-twenty-one in your discussion of the rotation of six-dimensional spaces of positive curvature, you said, 'From this it is evident that-' and immediately write your equation one-twenty-two. How did you do it? I'm not disagreeing, sir-on the contrary! But in an unpublished paper of my own I used a dozen pages to arrive at the same transformation. Did you have a direct intuition? Or did you simply omit publishing details? No criticism, I am impressed either way. Sheer curiosity."