"Brenda—"
She opened her eyes presently, bewildered, but she was unharmed.
"Oh—you—I was so frightened."
I held her as she recovered, and presently she was filling in all the grim details of her tragic little story. Whatever her brother Philip's propensities for gambling and bad companions, he had been no criminal. They had lost their father; had been truthful when they said they did not know what Professor Carson had been building in his lonely little laboratory. But they knew enough so that when the Phantom bandit began his mysterious raids, they suspected it was their father's ship; the laboratory explosion merely a blind. He had often mentioned, when they were children, that the dream of his life was to discover and perfect electronic invisibility.
"Albert Einstein of two hundred years ago," she was telling me now. "Father studied his writings and his theories very closely. He said that the secret of practical mechanical invisibility was clearly forecast by Einstein's discoveries."
"And you think now," I murmured, "your father is this mysterious Phantom raider?"
Her little face clouded. Her blue eyes, misty with Earthlight which was striking down upon us now through the clouds, gazed at me with a pathetic appeal.
"We did not know. We—we were afraid so. And then Philip got a message one night—"
Weird occurrence. Young Carson had been on the porch of their Long Island home. From the sky overhead, where nothing was to be seen, had come a little stab of waving white light. A helio signal. From their father? Certainly it seemed so. It told them to come secretly to Asteroid-9. He would be there, at the base of Andros. And so they had come to try and help their father.