I expected Zebbie to be picked. But there were three for me, one for Zebbie- my ballot.

I seemed to be the only one surprised. Zebbie said to Deety, "Ask to be relieved now, hon. The short-timer syndrome is bad for anyone but worse for a C.O.-it demoralizes her crew."

"Aunt Hilda, will you relieve me?"

I pondered it half a second. "I relieve you, Deety."

"Goody! I think I'll take a nap."

"I think you'll take the verniers. Zebbie and Jacob stay in the jobs they're in. Prepare to maneuver. Copilot, set for Oz. If you don't know how, ask your father."

"Set verniers for Oz?"

I took a deep breath to calm down. "Before anyone starts asking 'Why?' the answer is: Pipe down and do your job. Before we start on Teh axis, I want to ask questions. We talked to Glinda about our problem. We didn't talk directly to the others. I mean Ozma and Professor Wogglebug and the Little Wizard and possibly others. Family, magicians who can install two bathrooms in a Ford and never have it show can also help us spot vermin if we ask the right questions. Deety, are you having trouble setting for Oz?"

"Captain, why set verniers? Gay has our parking spot in her perms. Codeword 'Glinda."

A few seconds later Gay called out, "Hi, Tik-Tok!"

"Wel-come back, Miss Gay De-cei-ver. Glin-da told me that you would be gone on-ly a few mi-nutes, so I wai-ted here for you. I am deep-ly hap-py to see you a-gain."

The First Law of Biology

Zeb:

"Stand by to maneuver," I ordered-at the conn by Captain Sharpie's wish "Hello, Gay."

"Howdy, Zeb. You look hung over."

"I am. Gay Home!"

Arizona was cloudless. "Crater verified, Captain Hilda."

"Teh axis one plus-set, Captain," Deety reported.

"Execute!"

"No crater, Cap'n Auntie. No house. Just mountains." Deety added, "Teh one-minus-set."

"Roger, Deety. Routine check, Captain?"

"Voice routine, short schedule." (I think that is what got Sharpie elected permanent C.O.-she never hesitates.)

"Gay Deceiver. Sightseeing trip. Five klicks H-above-G." "Ogle the yokels at five thousand meters. Let's go!" "Deety, keep your thumb on the button. Gay-Miami Beach." Below lay a familiar strip city. "Captain?"

"Zebbie, note the crowded streets. Sunny day. Beaches empty. Why?" "Bogie six o'clock low!" Jake yelped.

"Gay Zoom!"

Earth-Teh-one-plus swam warm and huge. Opposite us a hurricane approached Texas. I asked, "Want to see more, Captain?"

"Zebadiah, how can we see more when we haven't seen any?"

"But Cap'n Sharpie has, Deety. Folks, I'm unenthusiastic about a world where they shoot without challenging. Jake, your bogie was a missile?"

"I think so, Zeb. Collision course with Doppler signature over a thousand knots and increasing."

"A missile-out of Homestead-analog, probably. Captain, these blokes are too quick on the trigger."

"Zebbie, I find empty beaches more disturbing. I can think of several reasons why they would be empty on a nice day-all unpleasant."

"Want to check San Diego? I can get more scram time by increasing Habove-G."

"No, we have over forty thousand analogs on this axis; we'll stick to doctrine. Shop each world just long enough to find something wrong-'Black Hats,' war, low technology, no human population, bad climate, overpopulated, or factor X. If we don't find our new Snug Harbor in the next four months, we'll consider returning to Doctor Smith's world."

"Hillbilly, if we wait there to have our babies, then wait again until they are big enough to travel, we'll never find Snug Harbor."

"I said, 'consider.' We may find a place to shack up for five months or so, then slam back to Galactic Patrol Prime Base hospital for the Grand Openings. Could be an empty world-no people, pleasant otherwise. Food is now no problem and we get water from Oz. All we lack is television-"

"That's no lack!"

"Deety, I thought you liked 'Star Trek'?"

"Auntie Captain, we've got our own star trek now."

"Hmm-Deety, you and I should go easy on this star trek. I'm going to I'm having my first one past forty and I'm going to be very careful-exercise, diet, rest, the works."

"I surrender. Let's get cracking, Cap'n Hillbilly."

"Take it, Zebbie."

"Copilot, execute!"

Earth-Teh -one-minus replaced Teh -one-plus. "Jacob, it doesn't look right. Astrogator, I want us up a hundred kilometers, over-make it Mississippi Valley about St. Louis. Want to change attitude?"

"Yes, please. Jake, point Gay at your target; it will skip setting angle." The craft's nose dipped and steadied.

"How's that?"

"Fine, Jake. Deety, set L axis plus transition ninety-nine thousand klicks."

"Set, Zebadiah."

"Execute." We popped out high over fields of ice. "Sneak up on it, Cap'n?"

"Never mind. Zebbie, that's what I call a hard winter."

"A long winter. Actually it's summer, I think; Earth-analogs should be in the same place in orbit as Earth. Jake?"

"By theory, yes. Doesn't matter either way; that's glaciation. Deety has set Teh -two-plus."

"We can't homestead on an ice sheet. Execute."

"Zebbie, how many ice ages so far?"

"Five, I think. Deety?"

"Five is right, Zebadiah. Plus two worlds with major war, one where they shot at us, and one so radioactive that we got out fast!"

"So we're hitting ice more often than not."

"Five to four has no statistical significance, Zebadiah. At least Aunt Hilda hasn't spotted even one 'Black Hat."

"Sharpie, how good are your magic spectacles?"

"Zebbie, if I see them walk, I'll spot 'em, no matter how they're disguised. In the simulations Glinda and Wizard cooked up, I spotted their gait every time Deety identified it by Fourier analysis."

"You feel confident, that's enough."

"Zebbie, I don't have clairvoyance; there wasn't time to train me. But Glinda got me highly tuned to their awkward gait, both with and without splints. I want to discuss something else. According to geologists, when we were home- Earth where we were born, I mean-we were in a brief warm period between glaciations."

"If geologists are right," I admitted.

"If so, we'll usually hit glaciation."

"Probably. 'If-"

"Yes, 'if-' But we now know what glaciation looks like. If you and Jacob and Deety can make it a drill, we can flip past ice ages as fast as you spot one."

"We'll speed it up. Jake."

"Zebadiah, wait!"

"Why, Deety? We're about to translate."

"Pop, you told me to set for Teh -five-plus."

"Jacob?" Captain Sharpie said.

"That's right, Captain."

"What's the trouble, Deety?"

"Aunt Hilda, I said that five-to-four had little statistical significance. But so far, all glaciations have been in Teh -minus. That could be chance but-"

-but doesn t look like it. You want us to explore axis Teh-plus first? Astrogator?"

'~No, no! Captain Auntie, I would like to see enough of Teh -minus to have a significant sample. At least a hundred."

"Jacob?"

"Hilda, if we check in one pseudodirection only-say Teh -minus-it'll be four or five times as fast as hunting back and forth between plus and minus. Deety can set with one click; Zeb can yell 'Execute!' as soon as you are satisfied."

"Jacob, we'll get Deety her sample. But faster. Astrogator, have our copilot set Teh -six-minus"

"Uh... set, Captain."

When Zebbie says 'Go,' Jacob, you and Deety flip them past as fast as you can without waiting for orders. All we'll be looking for is ice ages; we can spot one in a splitsecond. If anyone sees a warm world, yell 'Stop!' Deety, can Gay count them?"