"You're going to have to turn back to Earth, fellow. You can't land here. It's rough on us, missing a mail trip, but—"
Preston said impatiently, "Why can't I land? What the devil's going on down there?"
"We've been invaded," the tired voice said. "The colony's been completely surrounded by iceworms."
"Iceworms?"
"The local native life," the colonist explained. "They're about thirty feet long, a foot wide, and mostly mouth. There's a ring of them about a hundred yards wide surrounding the Dome. They can't get in and we can't get out—and we can't figure out any possible approach for you."
"Pretty," Preston said. "But why didn't the things bother you while you were building your Dome?"
"Apparently they have a very long hibernation-cycle. We've only been here two years, you know. The iceworms must all have been asleep when we came. But they came swarming out of the ice by the hundreds last month."
"How come Earth doesn't know?"
"The antenna for our long-range transmitter was outside the Dome. One of the worms came by and chewed the antenna right off. All we've got left is this short-range thing we're using and it's no good more than ten thousand miles from here. You're the first one who's been this close since it happened."
"I get it." Preston closed his eyes for a second, trying to think things out.