"Not on it. Inside it. It's an artificial asteroid."
They looked at him in astonishment, only half-comprehending.
"Already you know about the giant ship on the Moon, that housed so many men——"
"You mean," said Neil, "that the asteroid is a giant ship also?"
"It's more than one. On Mars we built four tremendous craft, each about one of your Earth miles in length and shaped like a quarter-slice from a round fruit. Then we took the four into space, one at a time, to the point where we wanted the asteroid's orbit to be. There we joined them together, like the quarters of the fruit fitted into shape again. The outer surfaces of them are roughcast to represent the natural rocky landscape of a little planet. And there we have a little world of our own, midway between Mars and your Earth."
The three Terrestrials were still mute with amazement. The Martian had recovered enough of his courage to laugh at them.
"I know that it sounds impossible. And so it must be, to such as you. Only on Mars, where we have the greatest metal resources, the most skillful mechanics, the wisest scientists in all the great universe, could such a thing be possible."
"Well," said Sukune, "what about it?"
"The Earth revolves around the sun every three hundred and sixty-five days, Mars in twice that. They will not come into opposition again for fully an Earth year from now. Naturally, Earth feels secure. Her mighty ships of war are idle, her millions of manpower loll in peaceful repose. They do not dream that this little artificial world may be dangerous. But it makes its journey around the sun in approximately four hundred and eighty days, and that can be speeded or slowed somewhat by means of tremendous rocket-engines. It will come into opposition with unthinking Earth in one hundred and fifty days, as I approximate it."