If his wives ever compared his videograms, Commander Norton thought with more amusement than concern, it would involve him in a lot of extra work. Now, he could make one long ’gram and dupe it, adding only brief personal messages and endearments before shooting the almost identical copies off to Mars and Earth.

Of course, it was highly unlikely that his wives ever would do such a thing; even at the concessionary rates allowed to spacemen’s families, it would be expensive. And there would be no point in it; his families were on excellent terms with each other, and exchanged the usual greetings on birthdays and anniversaries. Yet, on the whole, perhaps it was just as well that the girls had never met, and probably never would. Myrna had been born on Mars and so could not tolerate the high gravity of Earth. And Caroline hated even the twenty-five minutes of the longest possible terrestrial journey.

“Sorry I’m a day late with this transmission,” said the Commander after he had finished the general-purpose preliminaries, “but I’ve been away from the ship for the last thirty hours, believe it or not…”

“Don’t be alarmed—everything is under control, going perfectly. It’s taken us two days, but we’re almost through the airlock complex. We could have done it in a couple of hours, if we’d known what we do now. But we took no chances, sent remote cameras ahead, and cycled all the locks a dozen times to make sure they wouldn’t seize up behind us after we’d gone through…”

“Each lock is a simple revolving cylinder with a slot on one side. You go in through this opening, crank the cylinder round a hundred and eighty degrees and the slot then matches up with another door so that you can step out of it. Or float, in this case.”

“The Ramans really made sure of things. There are three of these cylinder-locks, one after the other just inside the outer hull and below the entry pillbox. I can’t imagine how even one would fail, unless someone blew it up with explosives, but if it did, there would be a second back-up, and then a third…”