We all finished at just about the same time, as per schedule, and went into Phase Two.
Monroe and I started work on building the dome. It was a simple pre-fab affair, but big enough to require an awful lot of assembling. Then, after it was built, we faced the real problem—getting all the complex internal machinery in place and in operating order.
Meanwhile, Tom Hawthorne took his plump self off in the single-seater rocket which, up to then, had doubled as a lifeboat.
The schedule called for him to make a rough three-hour scouting survey in an ever-widening spiral from our dome. This had been regarded as a probable waste of time, rocket fuel and manpower—but a necessary precaution. He was supposed to watch for such things as bug-eyed monsters out for a stroll on the Lunar landscape. Basically, however, Tom's survey was intended to supply extra geological and astronomical meat for the report which Monroe was to carry back to Army HQ on Earth.
Tom was back in forty minutes. His round face, inside its transparent bubble helmet, was fish-belly white. And so were ours, once he told us what he'd seen.
He had seen another dome.
"The other side of Mare Nubium—in the Riphaen Mountains," he babbled excitedly. "It's a little bigger than ours, and it's a little flatter on top. And it's not translucent, either, with splotches of different colors here and there—it's a dull, dark, heavy gray. But that's all there is to see."
"No markings on the dome?" I asked worriedly. "No signs of anyone—or anything—around it?"
"Neither, Colonel." I noticed he was calling me by my rank for the first time since the trip started, which meant he was saying in effect, "Man, have you got a decision to make!"
"Hey, Tom," Monroe put in. "Couldn't be just a regularly shaped bump in the ground, could it?"