He turned to King. "Doctor, does anything occur to you that might account for a phenomenon like Tycho?"
The Superintendent grasped the arms of his chair, then glanced at his palms. He fumbled for a handkerchief, and wiped them. "Go ahead," he said, almost inaudibly.
"Very well then." Harrington drew out of his briefcase a large photograph of the Moon — a beautiful full-Moon portrait made at Lick. "I want you to imagine the Moon as she might have been sometime in the past. The dark areas we call the 'seas' are actual oceans. It has an atmosphere, perhaps a heavier gas than oxygen and nitrogen, but an active gas, capable of supporting some conceivable form of life.
"For this is an inhabited planet, inhabited by intelligent beings, beings capable of discovering atomic power and exploiting it!"
He pointed out on the photograph, near the southern limb, the lime-white circle of Tycho, with its shining, incredible, thousand-mile-long rays spreading, thrusting, jutting out from it. "Here… here at Tycho was located their main power plant." He moved his fingers to a point near the equator and somewhat east of meridian — the point where three great dark areas merged, Mare Nubium, Mare Imbrium, Oceanus Procellarum —and picked out two bright splotches surrounded, also, by rays, but shorter, less distinct, and wavy. "And here at Copernicus and at Kepler, on islands at the middle of a great ocean, were secondary power stations."
He paused, and interpolated soberly: "Perhaps they knew the danger they ran, but wanted power so badly that they were willing to gamble the life of their race. Perhaps they were ignorant of the ruinous possibilities of their little machines, or perhaps their mathematicians assured them that it could not happen.
"But we will never know — no one can ever know. For it blew up and killed them — and it killed their planet.
"It whisked off the gassy envelope and blew it into outer space. It blasted great chunks off the planet's crust. Perhaps some of that escaped completely, too, but all that did not reach the speed of escape fell back down in time and splashed great ring-shaped craters in the land.
"The oceans cushioned the shock; only the more massive fragments formed craters through the water. Perhaps some life still remained in those ocean depths. If so, it was doomed to die — for the water, unprotected by atmospheric pressure, could not remain liquid and must inevitably escape in time to outer space. Its life-blood drained away. The planet was dead — dead by suicide!"
He met the grave eyes of his two silent listeners with an expression almost of appeal. "Gentlemen… this is only a theory, I realize… only a theory, a dream, a nightmare… but it has kept me awake so many nights that I had to come tell you about it, and see if you saw it the same way I do. As for the mechanics of it, it's all in there in my notes. You can check it — and I pray that you find some error! But it is the only lunar theory I have examined which included all of the known data and accounted for all of them."